AWS · Free tool
S3 storage class cost calculator
Plug in storage size, retention, request volume, and retrieval. See every S3 class side by side with the minimum duration penalty already applied. The cheapest class for cold data is usually wrong for warm data, and the math is what shows you which is which.
Cheapest class for this profile
Standard
$0/mo · $0/year
| Class | Storage | Requests | Retrieval | Penalty | Monthly |
|---|
Penalty column shows minimum-duration billing if your retention is shorter than the class minimum. Empty means retention covers the minimum and there is no penalty.
When the cheap class is the wrong class
Three patterns we see often. First, teams move logs to Glacier Flexible to save on the storage line, then their security team pulls a year of logs for an audit and the retrieval bill is six figures. Second, backup tools configured to push to Standard-IA, then deleting on a 14-day rotation. The 30-day minimum means you pay 30 days of storage for every 14 days of retention. Third, Intelligent-Tiering monitoring fees on tens of millions of objects under 128 KB, where the fee outpaces the savings.
The right class depends on access pattern, retention, and object size. The calculator covers the first two; for object size, expect penalty rows to dominate when your average object is small. We run the full math as part of the 14-day audit.
Run this on your real buckets
Free 14-day audit, read-only IAM role, one-page CFO summary.
We pull your actual S3 inventory, classify each bucket by access pattern, and recommend the storage class transitions that pay back. Including the ones that do not. Read-only, no card, report is yours.
Frequently asked
Which storage class is cheapest?
Glacier Deep Archive at $0.00099 per GB-month, but only if you keep the data 180 days or more and almost never read it. For data accessed irregularly but not predictably, Intelligent-Tiering is usually the safest default since it auto-moves objects between tiers and bills you for what they actually accessed.
What is the minimum duration penalty?
IA classes bill 30 days minimum, Glacier Instant and Flexible bill 90 days minimum, Deep Archive bills 180 days minimum. If you delete or transition an object before that, you still pay storage to the minimum. Hot data on a cold class loses the savings fast.
Are retrieval fees only for Glacier?
No. Standard-IA, One Zone-IA, and all three Glacier classes charge per-GB retrieval. Standard and Intelligent-Tiering frequent tier do not. The retrieval fee is the line item teams forget about when they move data to IA: a single audit pulling everything back can wipe out a year of storage savings.
How do lifecycle transition costs factor in?
Each lifecycle transition (Standard to IA, IA to Glacier, etc.) is a PUT request charged at the destination class rate. For buckets with billions of small objects, transition fees can dwarf the storage savings. The calculator below approximates this with the PUT input; for very small objects, factor 8 KB minimum object overhead into your math.
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