Video File Size Calculator
File size is just bitrate times duration. Pick your resolution, frame rate, and length below to see exactly how big your video will be, and how long it takes to upload. Quick answer: 10 minutes of 1080p at a standard 8 Mbps is about 600 MB.
Your Video
Estimated Size
Estimates use bitrate x duration / 8, plus 192 kbps audio. Real encoders vary with motion and detail.
Recording your screen or camera?
Recording Studio runs in your browser: screen plus camera together, green screen keying, 4K, and editor ready MP4/MOV exports. Free to use, and your footage never leaves your machine.
Open Recording StudioHow do I calculate video file size?
The formula is simple: file size = bitrate x duration / 8. Bitrate is measured in megabits per second (Mbps), and dividing by 8 converts bits to bytes. A 10 minute video at 8 Mbps works out to 8 x 600 seconds / 8 = 600 MB. Audio rides on top, but at 128 to 320 kbps it adds only about 1 to 2 percent.
Resolution and frame rate do not directly set the file size: bitrate does. But higher resolutions need higher bitrates to look good, which is why 4K files are so much larger than 1080p.
Common video sizes at standard bitrates
| Format | Bitrate | 10 minutes | 1 hour |
|---|---|---|---|
| 720p 30fps | 5 Mbps | 375 MB | 2.3 GB |
| 1080p 30fps | 8 Mbps | 600 MB | 3.6 GB |
| 1080p 60fps | 12 Mbps | 900 MB | 5.4 GB |
| 1440p 30fps | 16 Mbps | 1.2 GB | 7.2 GB |
| 4K 30fps | 45 Mbps | 3.4 GB | 20.3 GB |
| 4K 60fps | 68 Mbps | 5.1 GB | 30.6 GB |
Frequently asked questions
What bitrate should I use for screen recording?
Screen content compresses well because most of the frame does not change between frames. 4 to 6 Mbps is plenty for 1080p screen recording, and 15 to 25 Mbps for 4K. That is why this calculator's screen recording preset cuts the standard bitrate roughly in half.
Why is my real file bigger or smaller than the estimate?
Most encoders use variable bitrate, so the actual average depends on how much motion and detail your footage has. High motion gameplay comes out larger, static screen shares smaller. Codec matters too: H.265 and AV1 produce files roughly 30 to 50 percent smaller than H.264 at the same visual quality.
How much video fits on my drive?
Divide your free space by the per hour number above. A 256 GB drive holds about 70 hours of 1080p 30fps footage at 8 Mbps, or about 12 hours of 4K 30fps at 45 Mbps.
Does frame rate change file size?
Only through bitrate. Doubling the frame rate does not double the size, because consecutive frames are similar and compress efficiently. In practice 60fps needs roughly 50 percent more bitrate than 30fps at the same resolution, which is what the presets here use.