Video at 8 Mbps uses 60 MB per minute, or 3.6 GB per hour; at 50 Mbps an hour of footage takes 22.5 GB.
| Bitrate (Mbps) | MB per minute | GB per hour |
|---|---|---|
| 1 | 7.5 | 0.45 |
| 3 | 22.5 | 1.35 |
| 5 | 37.5 | 2.25 |
| 8 | 60.0 | 3.60 |
| 10 | 75.0 | 4.50 |
| 15 | 112.5 | 6.75 |
| 20 | 150.0 | 9.00 |
| 25 | 187.5 | 11.25 |
| 35 | 262.5 | 15.75 |
| 50 | 375.0 | 22.50 |
| 100 | 750.0 | 45.00 |
| 150 | 1,125.0 | 67.50 |
| 400 | 3,000.0 | 180.00 |
How it is computed
Size = bitrate × duration ÷ 8, because 8 bits make a byte. 1 MB = 1,000,000 bytes and 1 GB = 1,000 MB, as storage makers count. Add the audio bitrate for the total; container overhead is small.
FAQ
Why is my file smaller than the table?+
Most cameras and encoders use a variable bitrate: the number on the setting is a maximum or a target, and simple scenes use less.
Why does my computer show a smaller size in GB?+
Windows counts 1 GB as 1,073,741,824 bytes (a gibibyte), so the same file shows about 7% fewer “GB” than the table.