Restore Time Calculator
Estimate how long a backup restore will take based on data size and transfer throughput.
Inputs
Time for checksum verification, decompression, etc.
Total Restore Time
62.58minutes
Total Restore Time
1.043hours
Transfer Time
56.89minutes
Verification Time
5.69minutes
Step by step
Data size
500 GB = 512000 MB
= 512000 MB
Transfer time
512000 / 150 MB/s
= 3413.3 seconds
With verification overhead
3413.3 × (1 + 0.1)
= 3754.7 seconds
How it works
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
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.