S3 Storage Cost Calculator

cost = min(GB, 51200) x tier1 + next 460800 GB x tier2 + remainder x tier3, all per GB-month. S3 Standard storage is billed on a declining volume schedule, so the marginal GB gets cheaper once a bucket passes 50 TB and again past 500 TB, and the rate you feel is the blend of all three bands. Storage is metered in GB-month, so 60 TB present for half a month costs the same as 30 TB present for all of it. The rates above are user-supplied list prices — confirm them against the AWS S3 pricing page for your region before you commit a budget.

Tiering is why a single 600 TB bucket is cheaper than six 100 TB buckets in six accounts without consolidated billing, and why chargeback models built on a flat per-GB rate over-bill large teams.

This calculator takes 4 inputs: Average data stored per month, Price for the first 50 TB, Price for the next 450 TB, Price above 500 TB. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.

Actual usage. There is nothing to provision — AWS samples the bytes stored and averages them over the month into GB-month units, so deleting data reduces the bill part-way through a month.