Restore Time Calculator
Estimate how long a backup restore will take based on data size and transfer throughput.
About Restore Time Calculator
Restore time is dominated by the data transfer phase — total data divided by effective throughput — plus overhead for decompression, checksum verification, filesystem journal replay, and application-specific recovery steps. Understanding this total is critical for meeting Recovery Time Objectives (RTO) in disaster recovery planning.
Formula
Restore time
restore_time = (data_size / throughput) × (1 + verification_overhead)
- D
- data size in MB
- R
- throughput in MB/s
- v
- verification overhead fraction
Worked example
With the default values below, Restore Time Calculator returns Total Restore Time of 62.58. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Data Size to Restoreminimum 0.01 GB
- 500 GB
- Transfer Throughputminimum 1 MB/s
- 150 MB/s
- Verification Overheadaccepts 0–100 %
- 10 %
Results
- Total Restore Time
- 62.58 minutes
- Total Restore Time
- 1.043 hours
- Transfer Time
- 56.89 minutes
- Verification Time
- 5.69 minutes
Step by step
- 1Data size= 512000 MB
- 2Transfer time= 3413.3 seconds
- 3With verification overhead= 3754.7 seconds
Assumptions and limits
- The result is derived only from the 3 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 3 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
What affects restore throughput?
Network bandwidth (for remote backups), disk write speed at the destination, decompression CPU overhead, and whether the backup tool supports parallel stream restores all influence effective throughput.
How does this relate to RTO?
Recovery Time Objective is the maximum acceptable downtime. Your calculated restore time must be well within your RTO — if it exceeds it, you need faster storage, parallel restore, or a different backup architecture.