Object Storage Cost Calculator: Capacity, Requests, Retrieval and Egress
Estimate a provider-neutral object storage bill from average stored capacity, API requests, archive or
infrequent-access retrieval, and outbound data transfer. Enter the rates from your provider, contract, or invoice.
Private by design: calculator values stay in your browser and are not submitted.
Usage and rate inputs
Storage is prorated using a 30-day billing month.
Rates must all use this same currency.
Capacity
Use average billable capacity, not only the end-of-period value.
Requests
Retrieval and outbound transfer
Enter zero for storage classes without retrieval fees.
Allowance for this calculation period; enter zero if none applies.
Tip: press Ctrl/⌘ + Enter to recalculate.
Estimated object storage cost
Total for selected period—
Annualized run rate—
Average cost per day—
Billable outbound transfer—
Cost breakdown
Capacity—
Write / Class A requests—
Read / Class B requests—
All requests—
Retrieval—
Outbound transfer—
Share of total cost
Capacity
—
Requests
—
Retrieval
—
Egress
—
Usage summary
Average stored capacity—
Storage billing fraction—
Total requests—
Retrieved data—
Outbound data before allowance—
Free egress used—
Effective cost per stored TB-month—
Enter valid inputs to calculate object storage cost.
Worked example: 10 TB with requests, retrieval, and egress
For 10 TB stored over 30 days at 0.023 per GB-month, capacity costs 230. One million write requests
at 0.005 per 1,000 add 5, and 10 million reads at 0.0004 per 1,000 add 4.
Retrieving 1 TB at 0.01 per GB adds 10. If 2 TB leaves the provider, a 100 GB allowance leaves
1,900 GB billable; at 0.09 per GB, egress adds 171. The total is 420 for the selected 30-day period.
These are generic example rates, not a quote or a statement of any provider's current pricing.
Object storage cost formulas
Capacity in GB:entered capacity × decimal unit multiplier
Storage cost:average capacity in GB × price per GB-month × period days ÷ 30
Request cost:request count ÷ selected request billing unit × price per unit
Retrieval cost:retrieved GB × retrieval price per GB
Annualized run rate:period total × 365 ÷ period days
All data units are decimal billing units: 1 GB = 1,000,000,000 bytes, 1 TB = 1,000 GB, and 1 PB = 1,000 TB.
The 30-day storage proration is a scenario assumption; replace it with invoice-period data if your provider
calculates average capacity, hourly usage, or calendar-month proration differently.
What belongs in an object storage estimate?
Cost component
Input to collect
Common omission
Capacity
Average billable GB by storage class, including replicas where billed
Using month-end capacity for a workload that changed throughout the period
Requests
Operation counts mapped to the provider's request classes
Ignoring list, lifecycle, copy, multipart, or failed request charges
Retrieval
GB read from archive or infrequent-access classes
Treating retrieval as synonymous with internet egress
Egress
GB by destination and route after applicable allowances
Applying an internet rate to same-region, inter-region, or CDN traffic
Other services
Replication, transitions, inventory, monitoring, encryption keys, support, and tax
Assuming the four modeled components reproduce the complete invoice
How to choose rates and usage
Keep all inputs within the same account scope, region, storage class, and period.
Use invoice exports or metering data for average stored bytes and request counts when available.
Normalize provider request prices to the matching 1K, 10K, or 1M selector.
Use the marginal rate for a proposed change, or a blended rate when reproducing an existing bill.
Model different storage classes or pricing tiers separately, then add their totals.
Validate the estimate against a recent invoice before making a migration or budget decision.
Retrieval and egress may both apply to the same bytes. An archive download can incur a storage-class
retrieval fee and a separate network transfer fee. Check the source class, destination, region, and any
provider-specific free-transfer rules.
Frequently asked questions
What costs are included in the object storage estimate?
The calculator includes average capacity, two request classes, retrieval, and outbound transfer after a free allowance. It does not automatically include lifecycle transitions, replication, inventory, monitoring, minimum-duration or early-deletion charges, taxes, support, or provider-specific tiers.
Are retrieval and egress the same charge?
No. Retrieval is commonly a storage-class fee for reading archived or infrequently accessed data. Egress is a network transfer fee. Depending on the service and route, the same bytes can incur both.
Should storage capacity use GB or GiB?
Use the unit shown by the provider. This calculator uses decimal GB, TB, and PB. If billing uses GiB, convert measured bytes to GiB before entering a normalized rate or adjust the per-GB rate.
How are request charges calculated?
Request count is divided by the selected billing unit and multiplied by its price. Usage is not rounded into whole blocks; verify any minimum or rounding rules on the provider invoice.
How does the free egress allowance work?
The calculator subtracts the allowance from outbound data for the selected period and never lets billable egress fall below zero. Enter zero if the workload or route is not eligible.
Does the calculator support tiered pricing?
Not directly. Use a blended or marginal rate, or model each tier separately and add the totals.
Are my storage and pricing inputs uploaded?
No. Calculations, copied results, and CSV creation run locally in your browser.
Limits and disclaimer
This calculator is a planning aid, not a provider quote, invoice, tax calculation, or financial recommendation.
Pricing can vary by region, storage class, operation, destination, tier, commitment, currency conversion, and
contract. Minimum storage duration, early deletion, replication, lifecycle transitions, metadata, encryption
key operations, support, taxes, and discounts are excluded unless incorporated into your entered rates.
Confirm production budgets and migration decisions with current provider documentation, contract terms,
billing exports, and representative workload measurements.
