Data Retention Cost Calculator
Cost keeping data across storage tiers, at the prices you are charged.
In short
Formula: C = sum over tiers of (Volume_tier x Rate_tier x Months)
What this calculator does
Each tier is costed separately and summed, so no blended rate is invented. Tiers left at zero are excluded from the total rather than estimated. Cost per month and cost per TB retained are shown for allocation, following the FinOps unit-economics definition.
Use it to turn Currency, Retention period, Volume on the first tier, Price per TB-month, first tier, and the other shown inputs into a checked result you can compare, copy, or rerun with different assumptions.
The page shows the formula, a numeric worked example, and the assumptions that affect this professional & industry calculation.
Inputs and what they mean
- Currency
- — Amounts are shown in the currency you pick. No exchange rate is applied..
- Retention period
- — How many months the data is kept..
- Volume on the first tier
- — Volume kept on your hottest tier..
- Price per TB-month, first tier
- — Take this from your own bill or the provider's price page. No provider price is built in..
- Volume on a second tier (optional)
- — Optional component. Leave at 0 to exclude it from the result. Volume kept on a second, cheaper tier..
- Price per TB-month, second tier (optional)
- — Optional component. Leave at 0 to exclude it from the result. Take the rate from your own bill or the provider's price page; no provider price is built in..
- Volume on a third tier (optional)
- — Optional component. Leave at 0 to exclude it from the result. Volume kept on an archive tier..
- Price per TB-month, third tier (optional)
- — Optional component. Leave at 0 to exclude it from the result. Take the rate from your own bill or the provider's price page; no provider price is built in..
- Price as of (optional)
- — The date you took these prices. It is shown with the result so the figure is never read as a current vendor price..
- Price source (optional)
- — Where the prices came from. Shown with the result..
How to use it
- Enter your own figures — the calculator never fills in a rate, price or benchmark for you.
- Press Calculate to see the result.
- Read the formula, variables, assumptions and source below the result before you rely on it.
Formula
C = sum over tiers of (Volume_tier x Rate_tier x Months).
Inputs used: Currency, Retention period, Volume on the first tier, Price per TB-month, first tier, Volume on a second tier (optional), Price per TB-month, second tier (optional), Volume on a third tier (optional), Price per TB-month, third tier (optional), and other shown inputs.
Edge handling: Retention period is required.; Retention period cannot be negative.; Retention period must be no more than 1000000000000.; Volume on the first tier is required.; Volume on the first tier cannot be negative..
Worked example
12 TB hot and 40 TB archive kept for three years
- Start with Currency: USD, Retention period: 36, Volume on the first tier: 12, Price per TB-month, first tier: 23, Volume on a second tier (optional): 0, Price per TB-month, second tier (optional): 0.
- Apply the method: C = sum over tiers of (Volume_tier x Rate_tier x Months).
- Your own per-tier prices, taken from your bill.
Reading the result
The headline figure is the main answer. Any breakdown underneath shows the parts that make it up, so you can check the working and see what changes when you adjust an input.
Limitations and assumptions
- Inputs outside the supported range are rejected rather than forced into a result.
- The result depends on the values you enter for this data retention cost calculator; it does not supply missing rates, rules, prices, dates, or assumptions for you.
Reference: The Linux Foundation — Unit economics — FinOps Framework
Last reviewed:
Common questions
Where does this formula come from?
FinOps Framework capability: unit economics — cost per business unit is total cost for a period divided by the units delivered in the same period; a workload's cost is the sum of its metered components at the rates the organisation is charged. See the source link on this page.
What kind of calculation is this?
Per-tier volume multiplied by the user's per-TB-month price and the retention period, summed. Check the formula, example, and limitations on this page before using the result for a real professional & industry decision.
What are its limits?
Arithmetic over the figures entered — it cannot tell whether the underlying metering, logs or job records are complete. A figure from one run or one period is a weak description of ongoing behaviour. The result is only as current as the rates entered; a rate taken months ago is not a current cost. Tiered, committed-use and minimum-spend pricing are not modelled unless the user has already reduced them to the rates entered. Retrieval, early-deletion and request charges are not included unless the user folded them into the rates entered. Growth during the retention period is not modelled here — use the storage growth calculator first.
How do I use the Data Retention Cost Calculator?
Enter the required values for Currency, Retention period, Volume on the first tier, Price per TB-month, first tier, Volume on a second tier (optional), and the other fields shown. The calculator applies the formula on this page and shows the main result with any supporting breakdown so you can check the arithmetic.
What formula does the Data Retention Cost Calculator use?
C = sum over tiers of (Volume_tier x Rate_tier x Months) The visible formula section above lists the calculation path and the edge cases the page handles, so the result can be checked without relying on the form alone. Check the formula, example, and limitations on this page before using the result for a real professional & industry decision.
Can the Data Retention Cost Calculator be used for exact decisions?
Use it as a calculation aid, not as a substitute for checking the underlying rule, contract, policy, or professional advice that applies to your situation. When a result depends on local rules, personal details, prices, or dates, enter those values yourself and confirm them before acting.
Formula, source and verification
Per-tier volume multiplied by the user's per-TB-month price and the retention period, summed.
The question it answers: How large will this data store get, how much does compression save, and what does the retention policy cost?
The formula
C = sum over tiers of (Volume_tier x Rate_tier x Months)
- Vi — Volume on tier i
- (TB). Volume held on each tier; a tier left at zero is excluded.
- Ri — Price per TB-month on tier i
- (currency). Taken from the user's own bill or the provider's price page.
- m — Retention period
- (months). How long the data is kept.
Units: Terabytes and months in, currency out. Rates must be per TB-month in the currency selected.
What kind of calculation this is
Business input model. The answer depends on business figures only you can supply, such as your own costs, rates or volumes. No market or benchmark values are assumed for you.
Method
Each tier is costed separately and summed, so no blended rate is invented. Tiers left at zero are excluded from the total rather than estimated. Cost per month and cost per TB retained are shown for allocation, following the FinOps unit-economics definition.
Assumptions built into the result
- Mathematical: All the figures entered cover the same measurement period.
- Mathematical: Volumes, records and runs are counted consistently with the definitions the team has written down.
- Mathematical: Volumes are constant over the retention period.
- Mathematical: Rates are per TB-month, in the currency selected.
Figures this calculator will never guess for you
- No target, benchmark, industry average or typical figure is supplied for any value.
- A definition is never presented as a goal: the freshness formula is not a freshness target, and the growth formula is not a forecast of what growth should be.
- No provider price, rate card or list price is built in; every amount is entered by the user.
- No currency conversion is applied; amounts stay in the currency selected.
Limitations
- Arithmetic over the figures entered — it cannot tell whether the underlying metering, logs or job records are complete.
- A figure from one run or one period is a weak description of ongoing behaviour.
- The result is only as current as the rates entered; a rate taken months ago is not a current cost.
- Tiered, committed-use and minimum-spend pricing are not modelled unless the user has already reduced them to the rates entered.
- Retrieval, early-deletion and request charges are not included unless the user folded them into the rates entered.
- Growth during the retention period is not modelled here — use the storage growth calculator first.
Source and version
- Standard or reference
- FinOps Framework — unit economics — FinOps Foundation (FinOps Framework capability: unit economics — cost per business unit is total cost for a period divided by the units delivered in the same period; a workload's cost is the sum of its metered components at the rates the organisation is charged.)
- Published source
- The Linux Foundation — FinOps Framework
- Formula version
- Version 1
- Verification
- Reviewed against the cited source on
- How much weight the source carries
- Standards or government
- Applies to
- Currency
- Amounts stay in the currency you choose; no exchange rate is applied.
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