S3 Lifecycle Savings Calculator

net saving = (source rate − destination rate) x GB x months − (objects ÷ 1000 x transition charge); break-even months = transition cost ÷ monthly saving. A lifecycle transition is a one-off request charge billed per 1,000 objects, paid back by a lower monthly rate, so the break-even depends entirely on object count versus average object size. Millions of tiny objects can cost more to move than they will ever save, which is the same reason Standard-IA bills every object at a 128 KB minimum and holds it for a 30-day minimum duration. All rates here are user-supplied list prices to verify on the AWS S3 pricing page for your region.

It separates lifecycle rules that genuinely save money from the ones that quietly add a transition bill and an early-deletion exposure to a bucket full of thumbnails.

This calculator takes 6 inputs: Data being transitioned, Objects being transitioned, Source class price, Destination class price, Lifecycle transition charge, Months the data stays in the destination class. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.

Standard-IA bills a minimum of 128 KB per object and a minimum of 30 days. A 20 KB object is charged as 128 KB, so the cheaper per-GB rate is more than cancelled out and you still paid to transition it.