Bitrate and file size calculator
Duration times bitrate equals size: two fields and you know whether your file goes by email, by WeTransfer, or nowhere. The reverse calculation gives you the bitrate to set in Premiere to fit a size limit.
How big will the export be?
What bitrate fits a size limit?
Variable bitrate (VBR) gives a file slightly lighter or heavier than this calculation: the target you set in Premiere is an average, not a promise.
MB or MiB: why two numbers
A megabyte is 1,000,000 bytes for manufacturers and platforms; a "computing" megabyte (MiB) is 1,048,576 bytes, and that's what Finder and Explorer show. Same file, two numbers: 614 MB and 586 MiB. The tool shows both so an upload limit expressed in the other unit doesn't catch you out.
YouTube's recommended bitrates
Read from the official YouTube help page "Recommended upload encoding settings" on 26 September 2026. Values in Mbps for video only; YouTube also recommends 128 kbps for mono audio, 384 kbps for stereo and 512 kbps for 5.1.
| Resolution | SDR 24–30 fps | SDR 48–60 fps | HDR 24–30 fps | HDR 48–60 fps |
|---|---|---|---|---|
| 8K | 80 – 160 | 120 – 240 | 100 – 200 | 150 – 300 |
| 2160p (4K) | 35 – 45 | 53 – 68 | 44 – 56 | 66 – 85 |
| 1440p (2K) | 16 | 24 | 20 | 30 |
| 1080p | 8 | 12 | 10 | 15 |
| 720p | 5 | 7.5 | 6.5 | 9.5 |
| 480p | 2.5 | 4 | — | — |
| 360p | 1 | 1.5 | — | — |
These are upload recommendations, not what your viewers will get: YouTube re-encodes everything. Going higher stops helping past a point, but going too low shows up immediately in flat areas and fast motion.
Frequently asked questions
MB or MiB, which one should I look at?
Look at the unit of the limit you have to meet. Platforms and transfer services speak in MB (base 1000), your operating system shows MiB while sometimes calling them "MB". A 614 MB file shows up as 586 MB in Finder: not an error, the same number of bytes.
Why isn't my export exactly the calculated size?
Because variable bitrate moves with the picture: a locked-off shot uses less, a tracking shot through a forest uses more. The calculation gives the average. Add 5 to 10% of headroom when a limit is strict.
What bitrate for 1080p on YouTube?
YouTube recommends 8 Mbps for 1080p SDR at 24-30 fps, 12 Mbps at 48-60 fps (official help page, read 26 September 2026). In HDR, 10 and 15 Mbps.
What about a client who wants a light file?
Use the second calculation: from the imposed size and the duration you get the bitrate to type into Premiere (H.264, VBR 2-pass, target bitrate). Below roughly 2 Mbps at 1080p, compression starts to show.
Does audio count towards the size?
Yes, which is why there's a field for it. 192 kbps stereo is a sane default; over an hour that's still 86 MB.
Does this work for ProRes or DNxHD?
The maths is the same, but those formats have fixed bitrates per preset, and very high ones (hundreds of Mbps). Put the preset's bitrate in the video field and you get the size.