File Transfer Time Calculator
Estimate how long a transfer takes from its size and the link speed, allowing for protocol overhead, with throughput per hour and per day.
Free · No sign-up · Your inputs stay in your browser
Input
How long will a transfer take?
Output
6h 32m 9s
| Duration | 6h 32m 9s |
|---|---|
| Effective throughput | 10.63 MB/s (85.0 Mbit/s) |
| Per hour | 38.25 GB |
| Per day | 0.92 TB |
Network speeds are quoted in bits per second and file sizes in bytes, a factor of eight: a 100 Mbit/s line moves at most 12.5 MB/s. For a large one-off migration, compare against shipping a disk; AWS Snowball and similar exist because the arithmetic often favours a courier.
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About this tool
Method, assumptions, practical next steps, and limits.
Bits and bytes
Links are sold in bits per second and files measured in bytes. Divide by eight: a 1 Gbit/s link moves at most 125 MB/s, and in practice less once TCP, TLS and other traffic take their share. Disk speed at either end can be the real limit, especially for many small files.
Large migrations
At 100 Mbit/s, ten terabytes take more than nine days. For one-off moves that size, physical transfer services such as AWS Snowball exist because shipping disks is faster. For repeated syncs, rsync sends only what changed, and compressing first helps when the link rather than the CPU is the bottleneck.