Costs for FaaS services are based on execution time. Many providers calculate the execution time of each function in 100ms increments and always round up. The minimum execution time they will charge you for is 100ms, so any function that runs for less than 100ms will be billed at 100ms. AWS and Azure however, bills on a 1ms granularity. How much they charge per 100ms is based on memory size.

Below is a brief description of each field:

  • Number of executionstotal number of invocations for your function per month;
  • Average execution timeaverage execution duration of your function;
  • Memory allocationamount of memory your function needs for its work;
  • Use free tierwhether to include free tier quota in the monthly calculations.