S3 pricing explained: storage vs requests vs egress

If you are searching for a storage pricing calculator, you are usually trying to estimate S3-like object storage cost. The good news: most object storage bills can be explained by three buckets: storage, requests, and egress.

1) Storage (GB-month)

Storage is billed over time, often as "GB-month". If your storage grows over the month, use an average stored GB number, not the end-of-month peak.

Tool: Object storage cost.

2) Request fees (GET/PUT/LIST)

Many workloads treat request fees as noise, and often they are. But request fees can become meaningful when:

  • You store millions of small objects.
  • You have heavy LIST operations or frequent metadata reads.
  • Your application pattern causes many PUT/GET operations per GB stored.

Tools: S3 request cost and object storage cost (model requests as a separate line item).

3) Egress (data transfer out)

Egress is often the biggest surprise. If you read large amounts of data out of storage (downloads, analytics, cross-region access), the $/GB transfer charge can dominate.

Tool: Data egress cost.

Hidden items to watch for

  • Replication and cross-region copy: adds transfer/feature fees and duplicate storage. Start with copy storage pricing and S3 replication cost.
  • Different storage classes: IA/archive tiers can introduce retrieval and transition fees.
  • Growth over time: long retention or backups can turn a small daily ingest into a large monthly storage bill. Use DB storage growth as a simple estimator if you do not have a better model yet.

Storage classes: treat retrieval as a separate scenario

Colder storage classes often look cheap on GB-month, but they can add retrieval and minimum duration costs. The safest budgeting approach is to model a "retrieval month" separately (audits, backfills, restores) instead of smearing it across the whole year.

  • Storage: GB-month by class (hot vs cold vs archive).
  • Transitions: lifecycle moves can create extra requests and sometimes fees.
  • Retrieval: restore GB and restore requests when you access archived objects.

Recommended modeling approach

  1. Estimate average stored GB.
  2. Estimate monthly request volume (GET/PUT/LIST).
  3. Estimate egress GB/month (if any).
  4. Add replication/copy costs if you move data.

If you want a single page that ties these together, start with storage pricing calculator.

Related tools

Storage pricing calculator Object storage cost Copy storage pricing

Sources

Related guides

Storage Costs Explained (GB-month, requests, retrieval)
A practical storage cost model: GB-month, requests, retrieval, and transfer. Includes estimation checklist.
S3 CRR vs SRR cost: what changes (transfer, storage, requests)
A practical cost comparison of S3 cross-region replication (CRR) vs same-region replication (SRR). Compare transfer/feature fees, extra replica storage, and request costs - with calculators.
Copy storage pricing: what you pay for when data moves
A practical guide to pricing storage copy operations (cross-region copy, replication, backups) across S3-like object storage: transfer, requests, and extra storage.
S3 pricing: a practical model for storage, requests, egress, and replication
A practical S3 pricing guide: what to include (GB-month, requests, egress, replication) and how to estimate the key inputs without copying price tables.
S3 replication cost: how to estimate cross-region replication
A practical guide to estimating S3 replication cost: what data volume to count, which fees to expect, and how to model replica storage, requests, and transfer. Includes a fast checklist.
S3 to Glacier transfer cost: what to include in the move
A practical checklist for S3 to Glacier transfer cost: transition requests, minimum storage duration, and any transfer or rewrite overhead.

Related calculators

Data Egress Cost Calculator
Estimate monthly egress spend from GB transferred and $/GB pricing.
API Response Size Transfer Calculator
Estimate monthly transfer from request volume and average response size.
VPC Data Transfer Cost Calculator
Estimate data transfer spend from GB/month and $/GB assumptions.
Cross-region Transfer Cost Calculator
Estimate monthly cross-region transfer cost from GB transferred and $/GB pricing.
RPS to Monthly Requests Calculator
Estimate monthly request volume from RPS, hours/day, and utilization.
API Request Cost Calculator
Estimate request-based charges from monthly requests and $ per million.

FAQ

What are the main drivers of S3 cost?
Most S3-like bills come from storage (GB-month), requests (GET/PUT/LIST), and data transfer out (egress). Replication/copy can add transfer/feature fees plus duplicate storage.
Do request fees matter?
Often they're small, but at very high request volume (or many small objects), request fees can be material.
Why use average stored GB instead of end-of-month GB?
Storage is billed per GB-month. If storage grows during the month, average stored GB is a better planning input than the end-of-month peak.
Last updated: 2026-01-27