How to use the AWS Lambda Cost Calculator
- 1. Describe the functionInvocations per month, average duration and memory.
- 2. Pick optionsArchitecture, extra ephemeral storage and whether the free tier applies.
- 3. CalculateSee compute, request and storage costs, and the difference the other architecture makes.
How Lambda pricing works
Lambda bills two things. Requests cost $0.20 per million. Compute is measured in GB-seconds: memory in GB × duration in seconds, rounded up to the millisecond, for every invocation. Arm (Graviton) functions cost about 20% less per GB-second than x86. The monthly free tier covers 1 million requests and 4,00,000 GB-seconds, and ephemeral storage beyond the included 512 MB is billed separately. Prices are on-demand list prices checked on 10 November 2026, and every rate is editable, because cloud prices change. Confirm them on the provider's pricing page before you budget.
Memory also sets CPU power: a function given more memory often runs faster, so the cost can stay the same or even fall. Measure a few sizes before deciding.
Worked example
A function invoked 2 crore times a month, running 250 ms each time with 1 GB of memory on Arm, uses 50 lakh GB-seconds. After the free 4 lakh, compute costs $61.33, and 1.9 crore billed requests add $3.80. The total is $65.13, or ₹7,225 a month with GST. The same function on x86 would cost $16.67 more for compute.
Hidden costs
- CloudWatch Logs are billed separately and can exceed the Lambda cost for chatty functions.
- API Gateway or function URLs, data transfer and NAT gateways add to the bill.
- Provisioned concurrency, which keeps functions warm, is charged even when idle.
Frequently asked questions
Does a cold start cost extra?
Initialisation time is billed as part of the duration for most runtimes, so heavy start-up code adds cost.
When is EC2 cheaper than Lambda?
For steady, high traffic running all day, a right-sized server is often cheaper; compare with our EC2 calculator.
Is the Lambda cost calculator free?
Yes. You can open the Lambda cost calculator and change every input and rate without signing up. When you calculate a cost for the first time, we ask once for your name and WhatsApp number; after that it, and every other Uncodemy tool, opens straight away.