EC2 AMI Storage Calculator

billable GB per region = first image GB + (generations − 1) × changed GB; total = that × regions. EBS snapshots are incremental at block level within a region, so the second and later generations of an AMI only bill for blocks that actually changed — a 30 GB image rebuilt weekly with 6% churn costs far less than 12 full copies. Cross-region copies break the chain: the first copy into each region is a full baseline, which is why the region count multiplies the whole figure rather than adding a delta.

Retention is nearly free while churn is low and expensive the moment a build rewrites most of the filesystem, so the change rate — not the generation count — is the lever that decides whether an image pipeline is cheap.

This calculator takes 5 inputs: Used data in the first image, Blocks changed between builds, Image generations retained, Regions the image is copied to, Snapshot price per GB-month. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.

No. Deregistering removes the image but leaves the backing snapshots, which keep billing. Lifecycle policies must delete the snapshots as well, and this is one of the most common sources of quiet, long-lived EBS spend.