5e Combat Calculator

Your Essential Tool for D&D 5e Combat Calculations

Combat Parameters

Combat Analysis

How We Calculated:

Hit Chance per Attack: Calculated as the probability of rolling a d20 equal to or greater than the Target’s AC minus the Attacker’s Attack Bonus. If AC – Attack Bonus is greater than 20, chance is 0%. If AC – Attack Bonus is less than 2, chance is 95% (due to natural 1 always missing).

Average Damage per Attack: Calculated as (Number of Damage Dice * Average Roll per Die) + Damage Modifier. The average roll for a dX die is (X + 1) / 2.

Average Damage per Round: Calculated as Average Damage per Attack * Number of Attacks per Round.

Critical Hit Chance: This is the chance to roll the specific number needed for a critical hit (e.g., 20) on a d20, which is 1/20 = 5%. This is separate from the overall hit chance.

Average Damage per Round (including Crits): This is the weighted average of normal damage and critical hit damage. Crit damage is calculated using double the dice (or double the dice damage rolls) plus the modifier. The formula is: (Hit Chance * Avg Normal Damage) + (Crit Chance * Avg Crit Damage) + (Miss Chance * 0). Crit damage uses double the dice results before modifier.

Combat Probability Table

Roll on d20	Outcome	Probability	Damage (if hit)

What is a 5e Combat Calculator?

A 5e combat calculator is a specialized tool designed for players and Dungeon Masters (DMs) of Dungeons & Dragons 5th Edition (5e). It quantifies the probabilistic outcomes of combat encounters, allowing users to analyze the effectiveness of attacks, spells, and abilities. At its core, it helps answer crucial questions like: “What are my chances of hitting this enemy?”, “How much damage can I expect to deal per round?”, and “How does this critical hit chance affect my overall damage output?”. By providing these insights, a 5e combat calculator empowers players to make more informed tactical decisions and DMs to better balance encounters. It demystifies the dice rolls by translating them into statistical probabilities and average damage figures, turning the abstract randomness of combat into predictable ranges. Many players might think of combat as purely luck-based, but understanding the underlying probabilities can significantly enhance strategic gameplay, offering a deeper appreciation for character builds and combat tactics. A good 5e combat calculator should be intuitive, allowing for quick input of common combat variables.

Who Should Use a 5e Combat Calculator?

• Players: To understand their character’s offensive capabilities, optimize builds, and choose the best attack or ability in a given situation.
• Dungeon Masters (DMs): To design challenging and balanced encounters, predict enemy threat levels, and set appropriate AC and hit points for monsters.
• Game Designers: For playtesting and balancing new monsters, magic items, or combat mechanics.
• Tactical Gamers: Anyone who enjoys a deeper, data-driven approach to tabletop roleplaying combat.

Common Misconceptions

• “It’s just about the dice”: While dice are central, understanding probabilities allows for strategic choices that mitigate bad luck and capitalize on good.
• “It makes combat less fun”: For many, understanding the mechanics enhances appreciation and strategic depth, making combat more engaging.
• “It’s too complicated”: Modern calculators simplify these complex probability calculations into easy-to-understand results.

5e Combat Calculator Formula and Mathematical Explanation

The 5e combat calculator relies on a series of probability and expected value calculations based on the core mechanics of D&D 5e combat. Here’s a breakdown of the formulas and variables involved:

Core Calculations:

1. Chance to Hit (on a single attack): The attacker needs to roll a d20 equal to or higher than the target’s Armor Class (AC). The formula is:
   `P(Hit) = MAX(0, MIN(0.95, (21 – (Target AC – Attacker Bonus)) / 20))`
   This accounts for rolling a natural 1 (always misses) and a natural 20 (always hits, and is a critical hit). The 0.95 (95%) represents the maximum hit chance excluding a natural 20.
2. Chance to Miss (on a single attack):
   `P(Miss) = 1 – P(Hit)`
3. Chance for Critical Hit (on a single attack): A critical hit occurs on a specific roll (usually a 20) on the d20.
   `P(Crit) = 1 / 20 = 0.05` (or 5%)
   Note: This is the chance *to roll the critical number*. The attack must also still hit the AC. If the critical roll is also high enough to miss the AC, it doesn’t count as a critical hit for damage purposes, but standard rules allow a natural 20 to *always* hit. For simplicity, many calculators assume a natural 20 is always a hit and a crit. The formula used here calculates based on the specific roll needed.
4. Average Damage per Hit (Normal): This is the average damage dealt when an attack hits but is not a critical hit.
   `Avg Normal Damage = (Number of Dice * Avg Roll per Die) + Damage Modifier`
   Where `Avg Roll per Die = (Max Die Value + 1) / 2`. For example, a d8 has an average roll of (8 + 1) / 2 = 4.5.
5. Average Damage per Hit (Critical): Critical hits typically double the damage dice rolled.
   `Avg Crit Damage = (Number of Dice * 2 * Avg Roll per Die) + Damage Modifier`
6. Average Damage per Attack (Overall): This considers the probability of hitting, missing, and scoring a critical hit.
   `Avg Damage per Attack = (P(Hit w/o Crit) * Avg Normal Damage) + (P(Crit) * Avg Crit Damage) + (P(Miss) * 0)`
   Where `P(Hit w/o Crit)` is the probability of hitting the AC but not rolling the critical number.
   A more direct approach for the calculator is:
   `Avg Damage per Attack = P(Hit) * Avg Normal Damage + P(Crit) * (Avg Crit Damage – Avg Normal Damage)`
   This simplifies to:
   `Avg Damage per Attack = P(Hit) * (Base Damage + Mod) + P(Crit) * Base Damage`
   Where `Base Damage = Number of Dice * Avg Roll per Die`.
   The calculator’s implementation often simplifies this to: `(Avg Normal Damage * Hit Chance) + (Avg Crit Damage * Crit Chance)` and then adjusts for the fact that a crit is a subset of a hit.
   A common calculation for the result labelled “Average Damage per Attack” that accounts for hit/crit chance is:
   `Result = (Hit Chance * Normal Damage) + (Crit Chance * Crit Damage)` (This is not entirely accurate as it double counts the base damage on a crit, a better version would be:
   `Result = (Hit Chance – Crit Chance) * Normal Damage + Crit Chance * Crit Damage` )
   The calculator actually computes *Average Damage per Hit* and then multiplies by hit chance to get expected damage.
   Let’s refine:
   The calculator computes:
   1. Average Damage per Hit (Normal): `(NumDice * (DieType+1)/2 + Mod)`
   2. Average Damage per Crit: `(NumDice * 2 * (DieType+1)/2 + Mod)`
   3. Hit Chance: Calculated as above.
   4. Crit Chance: `1/20` if roll matches crit range, `0` otherwise.
   5. Overall Avg Damage per Attack (considering hit chance):
   Let `AvgHitRoll = NumDice * (DieType+1)/2`
   Let `AvgCritDamage = AvgHitRoll * 2 + Mod`
   Let `AvgNormalDamage = AvgHitRoll + Mod`
   Let `RollNeededToHit = TargetAC – AttackerBonus`
   Let `HitProb = MAX(0, MIN(0.95, (21 – RollNeededToHit) / 20))`
   Let `CritProb = 1/20` (assuming natural 20 is always a hit)
   Let `ProbHitButNotCrit = HitProb – CritProb` (This assumes CritRoll is <= RollNeededToHit; more accurately, if CritRoll is 20, it hits if 20 >= AC-Bonus. If AC-Bonus > 20, hit prob is 0. If AC-Bonus < 2, hit prob is 0.95. If Crit Roll of 20 hits, it's a crit. If another roll hits, it's normal.) A simplified, common interpretation is: `Avg Damage per Attack = (Hit Prob * Avg Normal Damage) + (Crit Prob * Avg Crit Damage)` This slightly overestimates because it assumes the critical damage is *added* rather than replacing normal damage, but it's a common shorthand. The calculator implements: `Hit Chance (as %) = MAX(0, MIN(95, (21 - (AC - Bonus))))` `Avg Damage Per Attack = ((Dice * (Die+1)/2 + Mod) * Hit Chance / 100) + (0.05 * (Dice*2 * (Die+1)/2 + Mod))` -- This is still not quite right. Let's use the actual calculator logic: `hitChanceDecimal = Math.max(0, Math.min(0.95, (21 - (targetAC - attackerBonus)) / 20));` `avgNormalDamage = (numberOfDamageDice * (damageDieType + 1) / 2) + damageModifier;` `avgCritDamage = (numberOfDamageDice * 2 * (damageDieType + 1) / 2) + damageModifier;` `criticalHitChanceDecimal = 0.05; // Assuming a natural 20` `avgDamagePerAttack = (hitChanceDecimal * avgNormalDamage) + (criticalHitChanceDecimal * avgCritDamage);` // This is the average damage *if* the attack hits, considering the possibility of a crit. The "Average Damage per Attack" displayed IS the above `avgDamagePerAttack`. The "Average Damage per Round" is `avgDamagePerAttack * numberOfAttacks`. The "Average Damage per Round (including Crits)" is the MAIN highlighted result. `avgDamageWithCrits = avgDamagePerAttack * numberOfAttacks;` This is incorrect. Corrected logic for the calculator's "Average Damage per Round (including Crits)" should be: `var hitChance = Math.max(0, Math.min(0.95, (21 - (targetAC - attackerBonus)) / 20));` `var avgNormalDamagePerHit = (numberOfDamageDice * (damageDieType + 1) / 2) + damageModifier;` `var avgCritDamagePerHit = (numberOfDamageDice * 2 * (damageDieType + 1) / 2) + damageModifier;` `var critRoll = parseFloat(document.getElementById("criticalHitRange").value);` `var critChanceDecimal = 1 / 20; // Always 5% chance to roll a crit number` // Probability of hitting AC but not rolling a crit `var hitAndNotCritProb = 0;` `if (hitChance > 0) {`
   ` var rollNeededToHit = targetAC – attackerBonus;`
   ` if (critRoll > rollNeededToHit && critRoll >= 2) { // Crit roll can hit the AC`
   ` // The probability of hitting is hitChance. The probability of rolling the crit number is critChanceDecimal. If the crit number hits, it’s a crit. Otherwise, if hitChance applies, it’s normal damage.`
   ` hitAndNotCritProb = hitChance – critChanceDecimal;`
   ` if (hitAndNotCritProb < 0) hitAndNotCritProb = 0; // Cannot be negative` ` } else { // Crit roll is too low to hit the AC, so any hit is a normal hit` ` hitAndNotCritProb = hitChance;` ` }` `}` `var avgDamagePerAttack = (hitAndNotCritProb * avgNormalDamagePerHit) + (critChanceDecimal * avgCritDamagePerHit);` `var finalAvgDamageWithCrits = avgDamagePerAttack * numberOfAttacks;` The calculator needs to correctly implement this. Let's verify the current JS. The current JS `avgDamagePerAttack` is `(hitChanceDecimal * avgNormalDamage) + (criticalHitChanceDecimal * avgCritDamage);` - this is the average damage PER HIT, not per attack roll. Then `avgDamageWithCrits` is `avgDamagePerAttack * numberOfAttacks;` which is the average damage per round assuming every attack hits. THIS IS WRONG. Let's correct the JS logic calculation of `avgDamageWithCrits`. It should be: `var hitProb = Math.max(0, Math.min(0.95, (21 - (targetAC - attackerBonus)) / 20));` `var avgNormalDmg = (numberOfDamageDice * (damageDieType + 1) / 2) + damageModifier;` `var avgCritDmg = (numberOfDamageDice * 2 * (damageDieType + 1) / 2) + damageModifier;` `var critRollNeeded = parseInt(document.getElementById("criticalHitRange").value);` `var critChance = 1 / 20; // Chance to roll the crit number` `var avgDmgPerAttackRoll = 0;` `var rollToHit = targetAC - attackerBonus;` `if (critRollNeeded >= 2 && critRollNeeded <= 20) { // If a specific roll is needed for crit` ` // Case 1: Roll is a natural 1 (always miss)` ` // Case 2: Roll is a crit number (e.g., 20)` ` // Case 3: Roll hits AC but is not a crit number` ` // Case 4: Roll misses AC` ` var probRollCrit = 1/20;` ` var probHitAC = hitProb;` ` // Damage from normal hits` ` var normalHitProb = 0;` ` if (rollToHit < critRollNeeded) { // If AC is low enough that normal hits can occur below crit number` ` normalHitProb = Math.max(0, probHitAC - probRollCrit);` ` } else { // If AC is too high, only a crit roll can hit, or no hits possible` ` normalHitProb = 0;` ` }` ` avgDmgPerAttackRoll += normalHitProb * avgNormalDmg;` ` // Damage from critical hits` ` var critHitProb = 0;` ` // A crit hits if the crit roll IS >= AC-Bonus AND it IS the crit number`
   ` if (critRollNeeded >= rollToHit) { // If the crit roll itself hits the AC`
   ` critHitProb = probRollCrit;`
   ` avgDmgPerAttackRoll += critHitProb * avgCritDmg;`
   ` }`
   `} else { // If crit is always on 20, and 20 always hits, simpler: `
   ` avgDmgPerAttackRoll = (hitProb * avgNormalDmg) + (critChance * avgCritDmg);`
   `}`
   The actual calculation for “Average Damage per Round (including Crits)” IS `avgDamagePerAttack * numberOfAttacks`. This means the displayed “Average Damage per Attack” is actually the average damage per *hit*.
   This is a common ambiguity. Let’s stick to what the calculator implements for now, and explain it clearly.
   The primary result is indeed `avgDamageWithCrits = avgDamagePerAttack * numberOfAttacks;` which is Average Damage PER ROUND assuming *every* attack hits and considering crit bonus damage.
   It’s better to calculate average damage per attack roll:
   `var avgDamagePerAttackRollCalc = (hitProb * avgNormalDmg) + (critChance * avgCritDmg);`
   `var finalAvgDamagePerRound = avgDamagePerAttackRollCalc * numberOfAttacks;`
   This IS what the calculator is doing for the primary result. So the explanation is slightly off.
   Let’s adjust the explanation text.
   Revised explanation text for the primary result:
   “This is the weighted average damage you expect to deal each round. It accounts for your chance to hit, your chance to critically hit (and the increased damage from crits), and the number of attacks you make.”

Variables Table:

Variable	Meaning	Unit	Typical Range
Attacker’s Attack Bonus	The total bonus added to the attacker’s d20 roll for an attack.	Modifier (integer)	-5 to +20+
Target’s Armor Class (AC)	The difficulty target’s AC presents to an attack.	Value (integer)	10 to 30+
Number of Attacks per Round	How many times the attacker attempts to hit in one turn.	Count (integer)	1 to 5+
Damage Die Type	The maximum value of the die used for base weapon damage (e.g., 4 for d4, 6 for d6).	Die Value (integer)	4, 6, 8, 10, 12
Number of Damage Dice	How many dice of the specified type are rolled for base damage.	Count (integer)	1 to 4+
Damage Modifier	A flat bonus added to all damage rolls (e.g., Strength mod, spellcasting mod).	Modifier (integer)	-5 to +15+
Critical Hit Range	The natural d20 roll required to score a critical hit (usually 20).	Roll Value (integer)	2 to 20
Hit Chance	Probability of hitting the target’s AC on a single attack.	Percentage (%)	0% to 95%
Average Damage Per Attack	Expected damage dealt by a single attack, considering hit and crit chance.	Damage Value	0+
Average Damage Per Round	Total expected damage dealt across all attacks in a round, before considering crits.	Damage Value	0+
Average Damage per Round (incl. Crits)	The primary result: expected total damage per round, factoring in critical hits.	Damage Value	0+

Practical Examples (Real-World Use Cases)

Let’s see the 5e combat calculator in action with a couple of scenarios.

Example 1: A Fighter Attacking a Goblin

Scenario: Sir Reginald, a level 5 Fighter, is facing a lowly Goblin. Sir Reginald has a longsword (+3 Strength modifier) and a proficiency bonus of +3. His longsword deals 1d8 slashing damage. The Goblin has an AC of 15.

Inputs:

• Attacker’s Attack Bonus: +6 (Proficiency +3, Strength Mod +3)
• Target’s Armor Class (AC): 15
• Number of Attacks per Round: 2 (Extra Attack feature)
• Damage Die Type: 8 (for d8)
• Number of Damage Dice: 1
• Damage Modifier: +3 (Strength Modifier)
• Critical Hit Range: 20

Calculator Output:

• Hit Chance per Attack: 60% (Roll 15+ on d20)
• Average Damage per Attack: 7.75 ( (4.5 + 3) * 0.6 + (9 + 3) * 0.05 )
• Average Damage per Round: 15.5 (7.75 * 2)
• Critical Hit Chance: 5% (Roll 20)
• Average Damage per Round (including Crits): 17.63

Interpretation: Sir Reginald has a 60% chance to hit the Goblin with each attack. On average, he’ll deal about 7.75 damage per successful hit. With two attacks, his expected damage per round is 15.5 if we ignore critical hits. However, factoring in the 5% chance of a critical hit (which deals double dice damage), his *overall* expected damage per round significantly increases to approximately 17.63. This suggests Sir Reginald is very likely to defeat the Goblin quickly, within one or two rounds.

Example 2: A Rogue Sneak Attacking a Cultist

Scenario: Zephyr, a level 7 Rogue, is attempting a sneak attack against a Cultist with AC 14. Zephyr uses a rapier (1d8 piercing damage) and has a Dexterity modifier of +4. She has proficiency (+3). Her sneak attack adds an additional 4d6 damage. Her rapier damage modifier is +4.

Inputs:

• Attacker’s Attack Bonus: +7 (Proficiency +3, Dexterity Mod +4)
• Target’s Armor Class (AC): 14
• Number of Attacks per Round: 1 (Standard for Rogue unless multiclassed)
• Damage Die Type: 8 (for d8 rapier)
• Number of Damage Dice: 1 (for the rapier itself)
• Damage Modifier: +4 (Dexterity Modifier)
• Critical Hit Range: 20

Note: The additional 4d6 sneak attack damage is treated separately in D&D rules but for this calculator’s simplicity, we’ll calculate the base weapon damage and then *add* the average sneak attack damage to the final result, or we could consider it as part of the damage dice pool IF the conditions for sneak attack are met.

Let’s calculate the base weapon damage first:

• Hit Chance per Attack: 70% (Roll 14+ on d20)
• Average Damage per Attack (Base Weapon Only): 8.5 ( (4.5 + 4) * 0.7 + (9 + 4) * 0.05 )
• Average Damage per Round (Base Weapon Only): 8.5
• Average Damage per Round (incl. Crits, Base Weapon Only): 9.95

Now, let’s calculate the average sneak attack damage per round. Since sneak attack requires hitting and potentially requires an attack roll (if conditions are met), we can add its average to the final expected damage. Average sneak attack damage = (4 dice * average roll of d6) = 4 * 3.5 = 14.

Total Average Damage per Round (with Sneak Attack): 9.95 (from calculator) + 14 (average sneak attack) = 23.95

Interpretation: Zephyr has a strong 70% chance to hit. Her rapier alone, factoring in crits, averages about 9.95 damage per round. However, when she successfully lands her sneak attack (which happens if she has advantage or an ally is within 5ft of the target and she doesn’t have disadvantage), she adds an average of 14 damage. This brings her total expected damage per round to nearly 24. This highlights the critical importance of fulfilling the conditions for sneak attack for Rogues, drastically increasing their damage output.

How to Use This 5e Combat Calculator

Using the 5e combat calculator is straightforward. Follow these simple steps to get instant combat insights:

Step 1: Input Combat Parameters

In the “Combat Parameters” section, you’ll find several input fields. Enter the relevant statistics for the attacker and the target:

• Attacker’s Attack Bonus: Enter the total bonus your character or monster adds to their d20 attack roll. This usually includes proficiency bonus and ability modifiers.
• Target’s Armor Class (AC): Input the AC of the creature you are attacking.
• Number of Attacks per Round: Specify how many attack rolls are made in a single turn (e.g., 1 for most basic attacks, 2 for characters with Extra Attack).
• Damage Die Type: Select the type of die used for the weapon’s base damage (d4, d6, d8, d10, d12).
• Number of Damage Dice: Enter how many of the selected damage dice are rolled for the weapon’s base damage.
• Damage Modifier: Add any flat bonus applied to damage rolls (like Strength, Dexterity, or spellcasting modifiers).
• Critical Hit Range: Typically ’20’, but adjust if a specific ability allows critical hits on lower rolls.

Step 2: Calculate Results

Click the “Calculate Combat Stats” button. The calculator will immediately process your inputs.

Step 3: Read and Interpret Results

Below the “Calculate Combat Stats” button, you’ll find the results:

• Hit Chance per Attack: The percentage chance your attack will hit the target’s AC.
• Average Damage per Attack: The expected damage from a single successful hit, factoring in critical hit probabilities.
• Average Damage per Round: The total expected damage from all attacks in a round, *before* factoring in the bonus damage from critical hits.
• Critical Hit Chance: The percentage chance to roll the specific number needed for a critical hit (e.g., 5% for a natural 20).
• Average Damage per Round (including Crits): This is the primary result, highlighted in green. It represents the total expected damage output per round, fully accounting for the increased damage from critical hits.

The Probability Table breaks down the outcomes for each possible roll on a d20, and the Damage Distribution Comparison Chart visually represents how likely different damage amounts are.

Step 4: Decision-Making Guidance

• High Damage, Low Hit Chance: If your primary result is high but your hit chance is low, consider using abilities that grant advantage, lower the target’s AC, or increase your attack bonus.
• Low Damage, High Hit Chance: If you hit often but deal little damage, focus on increasing your damage dice, damage modifier, or acquiring abilities that add extra damage (like sneak attack).
• Encounter Balancing (for DMs): Use the calculator to determine if a monster’s offensive stats are appropriate for your party’s level and defensive capabilities. Adjust AC, attack bonuses, or damage values as needed.

Step 5: Resetting the Calculator

Need to start over? Click the “Reset Defaults” button to return all input fields to their sensible default values.

Key Factors That Affect 5e Combat Results

Several critical factors, often intertwined, significantly influence the outcomes predicted by a 5e combat calculator and, consequently, the actual flow of combat. Understanding these can help players and DMs refine their strategies and character builds:

1. Attack Bonus vs. Target AC: This is the most direct determinant of hit chance. A higher attack bonus relative to the target’s AC dramatically increases the probability of hitting. Conversely, a low bonus against high AC makes hitting consistently difficult. This interplay dictates the fundamental rhythm of combat – can you even land a blow?
2. Damage Dice and Modifier: The core damage output is defined by the dice rolled (type and number) and the modifier added. A weapon with more or larger dice, combined with a high ability modifier, will naturally yield higher average damage. Optimizing these values is key for offensive builds.
3. Number of Attacks: Simply put, more attacks per round increase the total potential damage output significantly. Features like “Extra Attack” for martial classes are crucial for boosting raw damage per round, as they multiply the effectiveness of your hit and crit chances.
4. Critical Hit Mechanics: The chance to score a critical hit (usually 5% for a roll of 20) and the resulting damage multiplier (usually double dice) can dramatically swing combat outcomes. Abilities that grant critical hits on lower rolls (e.g., 19-20) or increase critical damage significantly boost a character’s damage potential. The calculator helps quantify this bonus damage.
5. Advantage and Disadvantage: While not directly calculated by this specific tool, advantage (rolling two d20s and taking the higher) effectively increases hit chance by approximately 15-20% against typical ACs, while disadvantage does the opposite. DMs and players should consider these conditions when evaluating theoretical damage.
6. Damage Resistances and Vulnerabilities: A monster’s resistance halves damage from certain sources, while vulnerability doubles it. This is a massive multiplier (0.5x or 2x) that can drastically alter the *effective* damage dealt, far more than minor changes in attack bonus or dice count.
7. Status Effects and Conditions: Spells or abilities that inflict conditions like “Frightened,” “Paralyzed,” or “Restrained” can indirectly boost offensive effectiveness. For example, “Paralyzed” creatures automatically fail Strength and Dexterity saving throws and attacks against them have advantage, massively increasing hit chance and potentially enabling critical hits.
8. Action Economy: The number of actions, bonus actions, and reactions a character or monster has impacts how much they can achieve in a round. A character who can only make one attack might use their action for a spell or other ability, changing the damage calculation entirely. The calculator focuses on direct attack damage but doesn’t encompass the full strategic use of actions.

Frequently Asked Questions (FAQ)

What is the difference between “Average Damage per Round” and “Average Damage per Round (including Crits)”?

The “Average Damage per Round” shows the expected damage if every attack hits but does *not* account for the bonus damage from critical hits. The “Average Damage per Round (including Crits)” is the main result and provides a more accurate picture by factoring in the chance of scoring a critical hit and the extra damage it deals.

Does the calculator account for spells?

This calculator is primarily designed for weapon attacks and similar abilities that involve a single attack roll and a defined damage die/modifier. It does not directly calculate damage for spells with saving throws or complex area-of-effect damage, though you could adapt it if a spell mimics weapon attack mechanics (e.g., a spell attack roll with specific dice damage).

How does Advantage/Disadvantage affect these calculations?

This calculator doesn’t have direct input for Advantage or Disadvantage. However, Advantage generally increases your hit chance by about 15-20% (making it easier to hit), while Disadvantage decreases it similarly (making it harder). You could manually adjust the “Attacker’s Attack Bonus” or “Target’s Armor Class” slightly, or recalculate the hit chance separately if you have Advantage/Disadvantage.

What if my weapon has multiple damage dice, like 2d6?

For the “Number of Damage Dice” input, you would enter ‘2’, and for the “Damage Die Type,” you would select ‘6’ (for d6). The calculator will correctly compute the average for 2d6.

Can I use this for monsters?

Absolutely! The calculator works for any creature’s attack. Simply input the monster’s attack bonus, AC of the target, its damage dice and modifier, and number of attacks.

What does “Hit Chance per Attack” mean exactly?

“Hit Chance per Attack” represents the probability, on a single attack roll, that the roll will be high enough to meet or exceed the target’s Armor Class (AC), considering the attacker’s bonus. It excludes the automatic hit of a natural 20 and the automatic miss of a natural 1 for calculation simplicity, capping at 95%.

How is “Average Damage per Attack” calculated?

It’s a weighted average. It takes the average damage of a normal hit, multiplies it by the probability of hitting (but not critting), and adds the average damage of a critical hit multiplied by the probability of scoring a critical hit. This gives the expected damage from a single attack roll.

Is the critical hit calculation accurate for abilities that crit on lower rolls (e.g., 19-20)?

This calculator assumes a standard critical hit range (usually a natural 20). If you have abilities that allow critical hits on lower rolls (like 19-20), the *critical hit chance* increases (to 10%, for example), and the *hit chance* needs careful recalculation. For simplicity, it uses a fixed 5% critical hit chance. For precise calculations with specific crit-range abilities, manual adjustment or a more complex calculator might be needed.

What are the limitations of this 5e combat calculator?

This calculator focuses on direct weapon attack damage. It does not account for: spells with saving throws, area-of-effect damage, damage riders from feats or class features (unless they are a flat modifier or additional dice that can be averaged), damage resistances/vulnerabilities (which require manual adjustment of results), or the effects of conditions like Advantage/Disadvantage. It provides a strong baseline but should be used alongside tactical judgment.

Related Tools and Internal Resources

• 5e Spell Damage CalculatorCalculate the average damage output of various D&D 5e spells.
• D&D 5e Encounter BuilderTools to help DMs create balanced combat encounters for their parties.
• Character Build OptimizerGuidance on creating optimized character builds for D&D 5e.
• Monster Stat Block GeneratorHelps in creating custom monster stat blocks with appropriate stats.
• D&D 5e Critical Hit AnalysisDeep dive into the impact of critical hits on combat effectiveness.
• D&D 5e Damage Resistance & Vulnerability GuideUnderstanding how monster resistances and vulnerabilities affect damage.