Practical guide
Lambda pricing: calculate requests and GB-seconds
estimate AWS Lambda GB-seconds and request cost. Includes a worked example, calculator scope, and practical questions.
Updated · Sources checked
Lambda has request and execution-duration components
A Lambda Functions estimate combines request count with memory-weighted execution duration. Duration usage is measured in GB-seconds, so the same number of invocations can have very different cost depending on configured memory and runtime.
Use billed duration where available, rather than only the application’s own handler timer. The calculator models x86 first-tier Functions rates in US East and does not cover every Lambda execution or pricing feature.
Worked example: ten million short invocations
Assume ten million invocations with an average billed duration of 200 milliseconds and 512 MB of configured memory. Convert 200 milliseconds to 0.2 seconds and 512 MB to 0.5 GB under the calculator’s 1,024 MB-per-GB conversion.
Total usage is 10,000,000 × 0.2 × 0.5 = 1,000,000 GB-seconds. Request quantity remains ten million. Multiply the applicable billable duration and requests by their separate prices after correctly treating any eligible shared allowance.
If duration increases to 300 milliseconds while count and memory remain constant, duration usage becomes 1.5 million GB-seconds. Request usage stays at ten million. This isolates a 50% duration increase rather than implying a 50% increase in every component of the application bill.
Treat free allowances consistently
The calculator can apply its documented Lambda free-tier quantities. Enable that scenario only when the allowance is available to the modeled usage. Other functions may already consume it; granting the full allowance independently to every function understates the account-level total.
The result excludes provisioned concurrency, additional ephemeral storage, other architectures or execution modes, transfer, and downstream services. API Gateway, CloudWatch Logs, and database work require their own estimates. Retries may also increase invocations beyond successful business operations.
Measure a representative distribution instead of selecting one fast invocation. If different memory configurations or workload classes run under the same application, calculate them separately and sum the components.
Frequently asked questions
Is duration in milliseconds or seconds? The calculator accepts milliseconds; the underlying usage calculation converts to seconds.
Does 512 MB mean 512 GB? No. Unit conversion is essential: the example uses 0.5 GB, which is why its duration usage is one million GB-seconds.
Calculate your scenario
Use the lambda cost calculator. Keep the displayed region, pricing date, billing units, and exclusions alongside your result. The arithmetic examples above illustrate usage or explicitly hypothetical rates; they are not AWS quotes.
Source
Billing structure checked against official AWS documentation on September 6, 2026.