Storage Size & Transfer Time Calculator
Convert between GB and GiB, see why a 1 TB drive shows as 931 GB on Windows, and estimate how long a copy will take.
Convert a size
| KB | 1000000000 |
|---|---|
| MB | 1000000 |
| GB | 1000 |
| TB | 1 |
| KiB | 976562500 |
|---|---|
| MiB | 953674 |
| GiB | 931 |
| TiB | 0.909 |
Drive makers and macOS count in powers of 1,000, so a 1 TB drive is 1,000,000,000,000 bytes. Windows divides by 1,024 but still prints “GB”, which is why the same drive shows as about 931 GB there.
How long will the copy take?
Uses the size above.
About 41 min 40 s
A rough estimate. Real speeds vary with the drive, the cable, and especially with many small files, which copy much slower than one large one.