AWS Lambda cost calculator
Requests, duration and ephemeral storage for one function, on x86 or Arm, in five AWS regions, with the free tier on or off.
Architecture
128 MB to 10,240 MB. CPU is allocated in proportion to memory.
The first 512 MB is included.
1,000,000 requests and 400,000 GB-seconds a month, shared by every function in the account, so leave it off when other functions already use it.
$29.60 a year · 500,000 GB-seconds a month
- Requests
- $0.80
- Duration
- $1.67
- Ephemeral storage
- $0.00
- Same workload on Arm (Graviton)
- $2.13
AWS list prices for us-east-1, retrieved 2026-09-19. The same requests, duration and memory on Arm (Graviton) would cost $0.33 a month less; a function can run faster or slower on the other architecture, so measure before switching. Sources and what this leaves out are below.
Share your number
5,000,000 Lambda requests a month at 200 ms and 512 MB on x86 cost about $2.47/month in us-east-1. tools.getfinops.cloud/lambda-cost-calculator
How AWS Lambda pricing works
A standard Lambda function is billed on three things. Requests: every invocation, at $0.20 per million in US East (N. Virginia). Duration: memory in GB multiplied by run time in seconds, rounded up to the next millisecond, billed per GB-second. Ephemeral storage: the /tmp space above the 512 MB every function gets for free, also per GB-second.
Duration has volume tiers. They are counted over every function on the same architecture in the same region of the account, so a large account pays less per GB-second for its later usage in the month. Arm functions have their own, lower, rates.
| Region | Requests (per 1M) | x86 per GB-second | Arm per GB-second | Ephemeral storage per GB-second |
|---|---|---|---|---|
| US East (N. Virginia) (us-east-1) | $0.20 | $0.0000166667 | $0.0000133334 | $0.0000000309 |
| US West (Oregon) (us-west-2) | $0.20 | $0.0000166667 | $0.0000133334 | $0.0000000309 |
| Europe (Ireland) (eu-west-1) | $0.20 | $0.0000166667 | $0.0000133334 | $0.000000034 |
| Europe (Frankfurt) (eu-central-1) | $0.20 | $0.0000166667 | $0.0000133334 | $0.0000000367 |
| Asia Pacific (Singapore) (ap-southeast-1) | $0.20 | $0.0000166667 | $0.0000133334 | $0.000000037 |
Duration columns show the first volume tier. Arm requests are priced the same as x86 in every region listed.
| GB-seconds per month | Per GB-second |
|---|---|
| First 6 billion | $0.0000166667 |
| Next 9 billion | $0.000015 |
| Over 15 billion | $0.0000133334 |
| GB-seconds per month | Per GB-second |
|---|---|
| First 7.5 billion | $0.0000133334 |
| Next 11.25 billion | $0.0000120001 |
| Over 18.75 billion | $0.0000106667 |
Worked example: an API backend
10,000,000 requests a month, 1 GB of memory, 120 ms average duration, in US East (N. Virginia), before the free tier.
GB-seconds = 10,000,000 × 0.12 s × 1 GB = 1,200,000
Requests = 10 × $0.20 = $2.00
Duration (x86) = 1,200,000 × $0.0000166667 = $20.00
Total = $22.00 a month on x86, $18.00 on Arm
With the free tier, if no other function in the account has used it, the x86 bill falls to $15.13.
Ways to lower a Lambda bill
- Right-size memory. Measure duration at several memory sizes and keep the cheapest one that meets your latency target.
- Try Arm. The GB-second rate is lower. Code in an interpreted runtime often moves without changes; native dependencies need an Arm build.
- Stop paying to wait. Time spent waiting on a downstream call is billed as duration. Make independent calls in parallel, and hand long waits to Step Functions.
- Watch the logs. Verbose logging from a busy function can cost more in CloudWatch Logs than the function itself.
Frequently asked questions
How is AWS Lambda priced?
You pay for requests and for duration. In US East (N. Virginia) requests cost $0.20 per million, and duration costs $0.0000166667 per GB-second on x86 for the first 6 billion GB-seconds a month. Ephemeral storage above the included 512 MB is billed per GB-second as well.
What is a GB-second?
Memory in GB multiplied by run time in seconds. A 512 MB function that runs for 200 ms uses 0.5 × 0.2 = 0.1 GB-seconds per invocation. Duration is rounded up to the nearest millisecond.
Is Arm (Graviton) cheaper than x86 on Lambda?
Per GB-second, yes: the first Arm tier in US East (N. Virginia) is $0.0000133334, about 20% below x86. The request price is the same. Whether your bill drops by that much depends on how long your code runs on each architecture, so test with your own workload.
What does the Lambda free tier cover?
1,000,000 requests and 400,000 GB-seconds a month, for x86 and Arm together. It does not apply to functions that use Provisioned Concurrency.
Does more memory always cost more?
Not always. Lambda gives a function CPU in proportion to its memory, so a CPU-bound function can finish sooner with more memory, and the shorter duration can outweigh the higher per-second rate. The open-source AWS Lambda Power Tuning tool measures this for a real function.
What does this calculator leave out?
Cold-start (INIT) time, which AWS bills for every function configuration (for on-demand .zip functions on managed runtimes since August 1, 2025): enter Billed Duration rather than the Duration metric to include it. Also Provisioned Concurrency, SnapStart, Lambda@Edge, data transfer, and the services a function calls, such as API Gateway, SQS, DynamoDB or CloudWatch Logs. Duration tiers apply to the total for all functions on one architecture in one region of an account (or across an organization with consolidated billing), so a single function reaches the lower tiers only if the account as a whole does.
Prices are public list prices in US dollars, before tax, retrieved on 2026-09-19 from the AWS Price List API (AWSLambda) and the AWS Lambda pricing page. They change; check the source before committing to a number. Your bill also depends on discounts, credits and usage this calculator does not see.