Rex says
Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.
Try a scenario
Click to load — tweak from there.Inputs
Result
Steady-state monthly cost
$56.35
Steady-state storage held
2,450
Day-1 storage (before retention fills)
1,000
Annualized cost
$676.20
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How to use this
- 1Enter full backup size (GB).
- 2Enter retention period (days).
- 3Enter compression/dedup factor.
- 4Enter daily change rate (incremental size vs full) (%).
- 5Enter backup strategy.
- 6Enter storage rate ($/GB-mo).
- 7Read your steady-state monthly cost on the right — it updates as you type.
- 8Hit Share to keep the scenario or send it to someone.
About this calculator
Backup cost isn't just the size of one backup — it's the accumulated footprint of every retained copy under your retention policy, and that footprint keeps growing until the oldest backups start aging out. This calculator models a common daily-full-backup pattern with a fixed retention window, computing total storage held at steady state (once the retention window has fully filled) accounting for a compression/dedup ratio, and multiplies by your storage rate for a monthly cost. It also shows storage at day one versus steady state, since teams often budget off the first backup's size and get blindsided once the retention window fills up weeks later. Incremental-forever or differential backup strategies use far less space than full daily backups for the same retention depth, and this tool includes an incremental-ratio input so you can model that pattern too instead of assuming every backup is a full copy.
Worked example
Using the values the calculator loads with:
Inputs
- Full backup size: 2000 GB
- Retention period: 30 days
- Compression/dedup factor: 0.5
- Daily change rate (incremental size vs full): 5 %
- Backup strategy: One full + daily incrementals
- Storage rate: 0.023 $/GB-mo
Results
- Steady-state monthly cost: $56.35
- Steady-state storage held: 2,450
- Day-1 storage (before retention fills): 1,000
- Annualized cost: $676.20
What each field means
Inputs
- Full backup size (GB)
- The full backup size used in the calculation, measured in GB. Starts at 2000 GB so you have a working example on load.
- Retention period (days)
- The retention period used in the calculation, measured in days. Starts at 30 days so you have a working example on load.
- Compression/dedup factor
- The compression/dedup factor used in the calculation. Starts at 0.5 so you have a working example on load. Accepted range: 0.05–1.
- Daily change rate (incremental size vs full) (%)
- The daily change rate (incremental size vs full) used in the calculation, measured in %. Starts at 5 % so you have a working example on load. Accepted range: 0–100 %.
- Backup strategy
- Pick the option that matches your situation — the maths changes per option. Choices: Full backup every cycle, One full + daily incrementals.
- Storage rate ($/GB-mo)
- The storage rate used in the calculation, measured in $/GB-mo. Starts at 0.023 $/GB-mo so you have a working example on load.
Results
- Steady-state monthly cost
- Returned as a money amount in US dollars and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Steady-state storage held
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Day-1 storage (before retention fills)
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Annualized cost
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
Why does full-backup-every-day cost so much more?
A daily full-backup strategy retained for 30 days stores roughly 30x a single compressed backup's size, since every copy is a complete independent snapshot. Switching to one full backup plus daily incrementals captures only the changed data each day — for a database changing 5% per day, 30 days of retention costs closer to 2.5x the full backup size instead of 30x, an order-of-magnitude difference.
What compression ratio should I actually assume?
Text-heavy data like databases and logs typically compress to 30-60% of raw size; already-compressed data like images, video, or encrypted volumes barely compresses at all (90-100% of raw size). Check your backup tool's own reporting after the first few cycles rather than guessing, since dedup ratios vary enormously by data type and backup software.
Does longer retention always mean proportionally higher cost?
With incremental-forever backups, no — cost grows roughly linearly with retention days but at the (much smaller) daily-change-rate slope, not the full-backup-size slope. Going from 30 to 90 days of retention on an incremental strategy might only add 20-40% to storage cost, while the same extension on a full-daily strategy would triple it.
Accuracy and limitations
- Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
- Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
- This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.
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Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Backup Storage & Retention Cost Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/backup-storage-retention-cost
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/backup-storage-retention-cost" target="_blank" rel="noopener">Backup Storage & Retention Cost Calculator — RevenueLab</a> (2026).</p>
Source: [Backup Storage & Retention Cost Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/backup-storage-retention-cost) (2026).