Database Backup Calculator
Size backup storage from database size, retention window, daily change rate and manual snapshots, and price the billable excess.
About Database Backup Calculator
Automated backups are one full baseline plus per-day incrementals of only the changed blocks, so retention multiplies the change rate rather than the database size — a 500 GB database changing 3% a day accrues about 15 GB per retained day, not 500 GB. AWS gives you backup storage equal to the total size of your databases free, so the bill is only what the retention window and manual snapshots push you past that line. The backup rate is an editable input with a realistic us-east-1 default, so confirm the current price with AWS for your region. Retention is the cheapest lever in a recovery plan and the easiest to get wrong in both directions: too short and you cannot recover from a slow-burn corruption, too long and you pay per GB-month for backups nobody will ever restore.
Formula
Database Backup
total backup = (full copy + size × daily change × retention days + snapshots × size × snapshot share) ÷ compression; billable = max(0, total − database size).
- full copy
- One baseline copy of the database that every incremental chain rests on
- daily change
- Share of blocks modified each day, which is what incrementals store
- free allowance
- Backup storage equal to the total database size, at no charge
- compression
- Snapshots are compressed, so stored bytes are less than logical bytes
Worked example
With the default values below, Database Backup Calculator returns Monthly Backup Cost of $60.80. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Database sizeaccepts 0–500,000 GB
- 500 GB
- Automated backup retentionaccepts 0–35 days
- 14 days
- Data changed per dayaccepts 0–100 %
- 3 %
- Manual snapshots retainedaccepts 0–100 snapshots
- 4 snapshots
- Average manual snapshot sizeaccepts 1–100 %
- 50 %
- Snapshot compression ratioaccepts 1–10 x
- 1.5 x
- Backup storage priceminimum 0 $/GB-month
- 0.095 $/GB-month
Results
- Monthly Backup Cost
- $60.80
- Total Backup Storage
- 1,140 GB
- Billable Backup Storage
- 640 GB
- Total Backup Storage
- 1 TiB
- Free Allowance
- 500 GB
- Annual Backup Cost
- $729.60
Step by step
- 1Values used
- 2Database Backup
- 3Monthly Backup Cost= 60.80
- 4Total Backup Storage= 1,140 GB
- 5Billable Backup Storage= 640 GB
- 6Total Backup Storage= 1,224,065,679,360
- 7Free Allowance= 500 GB
- 8Annual Backup Cost= 729.60
Assumptions and limits
- The result is derived only from the 7 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is Database Backup calculated?
total backup = (full copy + size × daily change × retention days + snapshots × size × snapshot share) ÷ compression; billable = max(0, total − database size). Automated backups are one full baseline plus per-day incrementals of only the changed blocks, so retention multiplies the change rate rather than the database size — a 500 GB database changing 3% a day accrues about 15 GB per retained day, not 500 GB. AWS gives you backup storage equal to the total size of your databases free, so the bill is only what the retention window and manual snapshots push you past that line. The backup rate is an editable input with a realistic us-east-1 default, so confirm the current price with AWS for your region.
Why does Database Backup matter?
Retention is the cheapest lever in a recovery plan and the easiest to get wrong in both directions: too short and you cannot recover from a slow-burn corruption, too long and you pay per GB-month for backups nobody will ever restore.
What values do I need to enter?
This calculator takes 7 inputs: Database size, Automated backup retention, Data changed per day, Manual snapshots retained, Average manual snapshot size, Snapshot compression ratio, Backup storage price. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.
Why do manual snapshots cost more than automated backups?
Automated backups roll off at the end of the retention window, but a manual snapshot lives until you delete it — including after the database itself is deleted. They also do not benefit from the same incremental chain once the source database is gone.
Does the free allowance cover all my databases?
The allowance is the total allocated size of your databases in that region, pooled — not a per-database figure. One database with a long retention window can consume the allowance earned by its quieter neighbours.