Azure Function Pricing Calculator

Estimate your monthly costs for running Azure Functions based on your anticipated usage and chosen plan.

Calculate Your Azure Functions Costs

Costs are calculated based on execution count, execution time, memory usage, and the selected pricing plan. Free grant tiers are applied first.

What is Azure Function Pricing?

Azure Functions pricing refers to the cost model for running serverless code on Microsoft Azure. Unlike traditional virtual machines or web apps where you pay for provisioned resources, Azure Functions allow you to pay only for the compute time you consume. This model is designed to be cost-effective for event-driven workloads, microservices, and intermittent tasks.

There are three main hosting plans for Azure Functions, each with a distinct pricing structure:

• Consumption Plan: The most “true serverless” option. You pay per execution, execution time, and memory used. It includes a generous free grant each month.
• Premium Plan: Offers features like VNet connectivity, unlimited executions, and longer runtimes, with a cost based on pre-warmed instances and consumption.
• Dedicated (App Service) Plan: Runs your functions on existing App Service plans, meaning you pay for the underlying VMs, similar to hosting web apps.

Who should use it? Developers and organizations looking to build and deploy event-driven applications, APIs, background processing tasks, or IoT data processing without managing servers. It’s ideal for workloads with variable or unpredictable traffic patterns.

Common Misconceptions:

• Completely Free: While there’s a free grant on the Consumption Plan, extensive usage will incur costs.
• Always Cheaper: For constant, high-throughput workloads, a Dedicated plan might become more cost-effective than Consumption.
• No Management Overhead: Serverless doesn’t mean no management; you still need to manage code, dependencies, scaling logic, and monitoring.

Azure Function Pricing Formula and Mathematical Explanation

The core idea behind Azure Functions pricing is to meter and charge for the resources consumed. The specific calculation varies significantly by plan.

1. Consumption Plan Pricing

The Consumption Plan is priced based on two main components: execution count and execution resources (CPU time and memory). A free monthly grant applies to both.

Formula Breakdown:

Estimated Monthly Cost = (Billable Executions * Cost per Execution) + (Billable GB-Seconds * Cost per GB-Second) + (Billable GB-Hours * Cost per GB-Hour)

Where:

• Executions: The total number of times your functions are triggered.
• Execution Time: The total CPU time consumed by all function executions.
• Memory Usage: The amount of memory allocated to each function instance.
• GB-Seconds: Calculated as (Memory in GB) * (Execution time in seconds). This is the primary metric for resource consumption.
• GB-Hours: Used for certain Premium/Dedicated scenarios, calculated as (Memory in GB) * (Execution time in hours).

Free Grant: The first 1 million executions and 400,000 GB-seconds of resource consumption are typically free each month per subscription.

2. Premium Plan Pricing

The Premium Plan has a predictable baseline cost plus consumption charges.

Estimated Monthly Cost = (Number of Premium Instances * Cost per Instance-Hour * Hours in Month) + (Billable GB-Seconds * Cost per GB-Second)

Note: Premium plans also have free grant benefits similar to the Consumption plan for the execution resources.

3. Dedicated (App Service) Plan Pricing

Here, you pay for the underlying App Service Plan tier, regardless of how much your functions actually run. The cost is based on the instance size and count.

Estimated Monthly Cost = (Cost per Hour for Selected Tier * Number of Instances * Hours in Month)

Variables Table (Illustrative – Actual prices vary by region and change over time)

Key Variables in Azure Functions Pricing

Variable	Meaning	Unit	Typical Range (Illustrative)
Number of Function Executions	Total triggers for your functions.	Count	100,000 – 100,000,000+
Average Execution Duration	Time taken per execution.	Milliseconds / Seconds	10 ms – 300,000 ms (5 mins max per execution)
Average Memory Usage	Memory consumed per execution.	MB	128 MB – 1536 MB (max per instance)
GB-Seconds	Billable compute resource consumed. (Memory GB * Execution Seconds)	GB-Seconds	1,000 – 10,000,000+
Premium Instances	Pre-warmed instances for low latency.	Count	1 – 100+
Premium Plan Execution Time	Total active time for premium instances.	Hours	~730 per instance per month
Premium Memory Usage	Total memory * time consumed.	GB-Hours	100 – 10,000+
Dedicated App Service Plan Tier	VM size and capabilities.	Tier Name	F1, B1, S1, P1v2, I1v2 etc.
Dedicated Plan Hours	Active time for the App Service Plan.	Hours	~730 per instance per month
Cost per Execution	Price per function trigger.	USD / 1 Million Executions	$0 – $0.20 (after free grant)
Cost per GB-Second	Price per GB-second consumed.	USD / GB-Second	$0 – $0.000016 (after free grant)
Cost per GB-Hour	Price per GB-hour consumed.	USD / GB-Hour	$0 – $0.00 (Often bundled in instance cost)
App Service Plan Cost	Monthly cost for the chosen tier.	USD / Month	$0 (Free Tier) – $700+ (Isolated)

Note: Exact pricing varies by region and is subject to change. Always refer to the official Azure Functions pricing page for the latest details.

Practical Examples of Azure Function Pricing

Let’s look at a couple of scenarios to understand how the costs might add up.

Example 1: High-Volume API (Consumption Plan)

Scenario: A popular web API built with Azure Functions, handling 50 million requests per month. Each request takes 100ms on average and uses 128MB of memory.

Inputs:

• Plan Type: Consumption Plan
• Executions: 50,000,000
• Average Duration: 100 ms
• Average Memory: 128 MB

Calculations:

• Total Execution Time (Seconds): 50,000,000 executions * (100 ms / 1000 ms/s) = 5,000,000 seconds
• Memory in GB: 128 MB / 1024 MB/GB = 0.125 GB
• Total GB-Seconds: 0.125 GB * 5,000,000 seconds = 625,000 GB-Seconds
• Free Grant Applied: 1,000,000 executions, 400,000 GB-Seconds
• Billable Executions: 50,000,000 – 1,000,000 = 49,000,000
• Billable GB-Seconds: 625,000 – 400,000 = 225,000 GB-Seconds

Estimated Cost (Illustrative):

• Cost for Executions: (49,000,000 / 1,000,000) * $0.20 = $49 * $0.20 = $980
• Cost for GB-Seconds: 225,000 * $0.000016 = $3.60
• Total Estimated Monthly Cost: $980 + $3.60 = $983.60

Interpretation: While serverless is pay-per-use, high-volume workloads can become significant costs. Optimizing function duration and memory is crucial.

Example 2: Background Processing Task (Dedicated Plan)

Scenario: A company runs a scheduled background task (e.g., nightly data aggregation) using Azure Functions. The task runs consistently for 1 hour every night and requires moderate resources. They already have an S1 Standard App Service Plan for other web apps.

Inputs:

• Plan Type: Dedicated (App Service) Plan
• App Service Plan Tier: S1 (Standard)
• Dedicated Plan Hours: 30 hours (1 hour/night * ~30 days)

Calculations:

The cost is primarily the fixed cost of the S1 App Service Plan, plus any function-specific charges if they exceed the plan’s capacity (less common for background tasks within a plan).

Estimated Cost (Illustrative):

• Cost of S1 Plan (approx.): $70 – $100 per month (depending on region and commitment)
• Cost for function runtime: Included in the S1 Plan cost.
• Total Estimated Monthly Cost: ~$70 – $100

Interpretation: For predictable, sustained workloads, using a Dedicated plan can be more cost-effective than Consumption, as you leverage existing infrastructure and avoid per-execution charges. The cost is fixed regardless of the number of executions within the plan’s limits.

How to Use This Azure Function Pricing Calculator

Our calculator simplifies estimating your Azure Functions costs. Follow these steps:

1. Select Pricing Plan: Choose ‘Consumption’, ‘Premium’, or ‘Dedicated’ based on your intended hosting plan. The input fields will adjust accordingly.
2. Enter Usage Details:
   • Consumption Plan: Input your estimated monthly ‘Number of Function Executions’, ‘Average Execution Duration’ (in milliseconds), and ‘Average Memory Usage’ (in MB).
   • Premium Plan: Specify the ‘Number of Premium Plan Instances’ (pre-warmed), ‘Premium Plan Execution Time’ (in hours), and ‘Premium Memory Usage’ (in GB-Hours).
   • Dedicated Plan: Select your ‘Dedicated App Service Plan Tier’ and the total ‘Dedicated Plan Hours’ you expect to use per month.
3. Validate Inputs: Ensure all numbers are non-negative. The calculator provides inline error messages if values are invalid.
4. Calculate Price: Click the ‘Calculate Price’ button.
5. Interpret Results:
   • The main result shows your estimated total monthly cost.
   • Intermediate values (GB-Seconds, Executions, Billable Memory, Instance Hours) provide a breakdown of resource consumption.
   • The ‘Key Assumptions’ section clarifies the pricing metrics used.
6. Use Decision Guidance: Compare costs across different plans or tweak input values to see how optimizations (like reducing execution time or memory) impact your final bill.
7. Reset Defaults: Click ‘Reset Defaults’ to revert all fields to their initial sample values.
8. Copy Results: Click ‘Copy Results’ to copy the main cost, intermediate values, and key assumptions to your clipboard for reporting or sharing.

This tool helps you budget effectively and make informed decisions about your Azure Functions architecture.

Key Factors That Affect Azure Function Pricing Results

Several factors influence your Azure Functions bill. Understanding these helps in cost optimization:

1. Hosting Plan Choice: This is the most significant factor. Consumption offers pay-per-use flexibility, Premium adds performance features at a higher base cost, and Dedicated leverages existing App Service plans.
2. Execution Count: More triggers mean higher costs on the Consumption plan. Optimizing event sources or batching operations can reduce this.
3. Execution Duration: Longer-running functions consume more CPU time. Optimizing code, using efficient algorithms, and asynchronous patterns reduce duration.
4. Memory Allocation: Functions requiring more memory cost more per second/minute. Right-sizing memory is crucial; too little can cause performance issues, too much increases cost.
5. Free Grant Utilization: The Consumption plan’s free tier (1M executions, 400K GB-seconds) significantly reduces costs for low-usage scenarios. Ensure your usage doesn’t consistently exceed this if you want to leverage it fully.
6. Number of Instances (Premium/Dedicated): For Premium, more pre-warmed instances mean higher baseline costs but lower latency. For Dedicated, more instances or higher tiers increase the base cost.
7. Region: Azure service pricing varies by geographical region. Costs in West US might differ from East US or Europe.
8. Networking Egress: While not directly part of function execution cost, data transferred out of Azure regions (egress) incurs charges. Complex data processing might involve significant egress costs.
9. Premium Features: Features like VNet integration in the Premium plan add to the cost.
10. Support Plans: Different Azure support plans have associated costs that aren’t calculated here but are part of the overall Azure spending.

Frequently Asked Questions (FAQ)

Q1: Is the Azure Functions Consumption plan truly “pay-per-execution”?

A: Largely, yes. You pay for executions, execution time (measured in GB-seconds), and outbound data transfer. However, there’s a free grant that covers the first 1 million executions and 400,000 GB-seconds monthly, making low-usage scenarios effectively free.

Q2: When is a Premium plan more cost-effective than Consumption?

A: Premium plans become cost-effective when you need features like VNet connectivity, longer execution times, or consistent low latency (via pre-warmed instances) and your workload is substantial enough that the base cost of the Premium plan is less than the consumption charges would be on the Consumption plan.

Q3: How does running functions on a Dedicated App Service Plan affect cost?

A: You pay for the App Service Plan itself (monthly VM costs). Function executions are essentially free within the plan’s capacity. This is ideal if you already have an App Service Plan or have predictable, high-volume workloads where the fixed cost is lower than Consumption plan variable costs.

Q4: What are GB-Seconds and why are they important?

A: GB-Seconds is the unit for measuring the compute resources consumed by your functions. It’s calculated by multiplying the memory allocated to your function (in GB) by the duration of its execution (in seconds). This metric helps Azure meter and charge for resource usage accurately on the Consumption plan.

Q5: Can I mix and match plans for different functions within the same application?

A: No, an Azure Functions app (the host process) is tied to a single hosting plan. You would need separate Function Apps to host functions on different plans (e.g., one Consumption, one Premium).

Q6: How does network egress pricing impact my total cost?

A: Data transferred *out* of Azure data centers incurs costs, charged per GB. While function execution costs cover compute, if your functions process and send large amounts of data externally, egress charges can become a significant portion of your bill.

Q7: Are there ways to optimize my Azure Functions costs?

A: Yes. Optimize code for faster execution, right-size memory allocation, choose the most cost-effective plan for your workload type, leverage the free grant on the Consumption plan, use Durable Functions for long-running workflows to manage execution efficiently, and monitor costs using Azure Cost Management.

Q8: Does the calculator include costs for triggers and bindings?

A: The calculator primarily focuses on the compute costs (execution time, memory, instance hours) based on the selected plan. Costs related to specific triggers (like Logic Apps, Event Hubs) or data storage/transfer associated with bindings are typically separate Azure service charges and not included here.