By Ahsan Khowaja · Updated 27 October 2026
How to use the bitrate calculator
- Pick a job. The bitrate of a video file tells you how heavily an existing file is compressed. The video bitrate to set works backwards from a size limit to the number you type into an encoder.
- Enter the size. MB and GB here are decimal: 1 MB is 1,000,000 bytes and 1 GB is 1,000,000,000 bytes, which is how macOS, phones and storage makers count. If you read the size in Windows Explorer, choose MiB or GiB instead, because Windows divides by 1,024 but still labels the result "MB" and "GB".
- Enter the running time in hours, minutes and seconds.
- Enter the audio bitrate. 128 kbps is a common AAC stereo setting; set it to 0 if the file has no sound or you only want the overall figure.
The result is shown in Mbps (megabits per second) and kbps (kilobits per second), because encoders use one or the other. 1 Mbps is 1,000 kbps.
The bitrate formula
Bitrate is the amount of data per second of video. Files are measured in bytes, bitrates in bits, and there are 8 bits in a byte, so:
Bitrate (bit/s) = file size (bytes) × 8 ÷ length (seconds)
Divide the result by 1,000 for kbps or by 1,000,000 for Mbps. Turned around, this is also a bitrate to file size formula: size in bytes = bitrate × seconds ÷ 8. The video file size calculator does that direction, including how long a card or drive will record for, so you don't need a separate bitrate to storage calculator.
Worked example: bitrate of a video file
A 1.2 GB recording that runs 10 minutes:
- 1,200,000,000 bytes × 8 = 9,600,000,000 bits
- 10 minutes = 600 seconds
- 9,600,000,000 ÷ 600 = 16,000,000 bit/s = 16 Mbps (16,000 kbps)
That figure covers everything in the file. If the audio track is 128 kbps, the video alone is 16,000 − 128 = 15,872 kbps, about 15.87 Mbps. The same file uses 120 MB per minute, which is a useful number when you are deciding what to keep.
A 700 MB film that runs 1 hour 30 minutes works out at 5,600,000,000 bits ÷ 5,400 s = 1,037,037 bit/s, or about 1.04 Mbps. That is low for 1080p and explains why old downloads of that size look soft.
Video bitrate calculator for a target file size
When a platform or a form has a size limit, you want the opposite answer: the bitrate that lands under the limit. The video bitrate calculator mode does three things:
- Converts the target size to bits and divides by the length, giving the total bitrate the file can have.
- Subtracts the audio bitrate, because the audio track takes its share of every second.
- Reports the remaining video bitrate, which is the number most encoders ask for.
Video bitrate = (target bytes × 8 ÷ seconds) − audio bitrate
Worked example: a 100 MB limit for a 2-minute clip
- 100,000,000 bytes × 8 = 800,000,000 bits
- 800,000,000 ÷ 120 s = 6,666,667 bit/s total (6.67 Mbps)
- Minus 128,000 bit/s of audio = 6,538,667 bit/s, so set the video to about 6.54 Mbps (6,539 kbps)
The audio takes 128,000 × 120 ÷ 8 = 1,920,000 bytes, which is 1.92 MB or 1.92% of the file. For a 30-second clip that must fit in 8 MB with 96 kbps audio, the video bitrate is 2,133 − 96 = 2,037 kbps, about 2.04 Mbps. For a one-hour recording that has to fit in 2 GB with 192 kbps audio, it is 4,444 − 192 = 4,252 kbps.
Encoders don't hit a bitrate exactly, and the container adds a little overhead, so aim 2–5% below the limit. If the result is well under 1 Mbps for HD footage, the picture will fall apart; drop the resolution or frame rate instead of squeezing the bitrate further.
HandBrake, OBS and other encoders
In HandBrake, the Video tab offers Constant Quality or Avg Bitrate (kbps). Use the kbps figure from this bitrate calculator in the Avg Bitrate box and turn on 2-pass encoding so the encoder spreads the budget sensibly across the film. Constant Quality mode ignores bitrate targets, so the file size is unpredictable there. For a HandBrake bitrate calculator the same subtraction applies: HandBrake sets the audio bitrate on its own Audio tab, and that figure comes off your total.
Streaming software such as OBS asks for a Video Bitrate in kbps and an Audio Bitrate separately. For a live stream the figure to respect is your upload speed rather than a file size: leave headroom of at least a quarter of the connection, because the stream must never exceed it.
YouTube bitrate calculator: recommended upload bitrates
YouTube publishes recommended bitrates for uploads on its recommended upload encoding settings page. These are recommendations, not limits: YouTube says no bitrate limit is required, and it re-encodes everything anyway. The SDR figures as of that page:
| Resolution | 24, 25 or 30 fps | 48, 50 or 60 fps |
|---|---|---|
| 2160p (4K) | 35–45 Mbps | 53–68 Mbps |
| 1440p | 16 Mbps | 24 Mbps |
| 1080p | 8 Mbps | 12 Mbps |
| 720p | 5 Mbps | 7.5 Mbps |
| 480p | 2.5 Mbps | 4 Mbps |
| 360p | 1 Mbps | 1.5 Mbps |
YouTube's recommended audio bitrates on the same page are 128 kbps for mono, 384 kbps for stereo and 512 kbps for 5.1 surround. To use this page as a YouTube bitrate calculator, pick the row for your resolution and frame rate, then put that figure into the video file size calculator to see how big the upload will be.
For live streaming, Twitch's broadcasting guidelines suggest 6,000 kbps for 1080p at 60 fps, 4,500 kbps for 1080p at 30 fps or 720p at 60 fps, and 3,000 kbps for 720p at 30 fps, with constant bitrate (CBR) and AAC audio at 96 kbps for maximum compatibility.
Audio bitrate calculator: how much the sound costs
Audio is cheap next to video, but over a long recording it adds up. The audio bitrate calculator part of the result (the "Audio takes up" row) is simply audio kbps × 1,000 × seconds ÷ 8 bytes:
| Audio bitrate | Per minute | Per hour |
|---|---|---|
| 64 kbps | 0.48 MB | 28.8 MB |
| 96 kbps | 0.72 MB | 43.2 MB |
| 128 kbps | 0.96 MB | 57.6 MB |
| 192 kbps | 1.44 MB | 86.4 MB |
| 256 kbps | 1.92 MB | 115.2 MB |
| 320 kbps | 2.4 MB | 144 MB |
For a podcast or a lecture recording with a static picture, the audio may be most of the file, and the video bitrate can go very low without anyone noticing.
DVD bitrate calculator
A single-layer DVD holds 4.7 GB (4,700,000,000 bytes). A film that fills the whole disc over 2 hours has an average bitrate of 4,700,000,000 × 8 ÷ 7,200 s = 5,222,222 bit/s, about 5.22 Mbps including audio. To use this page as a DVD bitrate calculator for authoring, enter 4.7 GB as the target, the total running time of everything on the disc, and your audio bitrate, then set the video encoder a little under the result to leave room for menus and subtitles.
What the result does and doesn't tell you
- The calculator gives the average bitrate. Variable-bitrate files spend more on busy scenes and less on still ones, so a player's instantaneous reading will swing above and below this figure.
- Bitrate measures data, not quality. Two files at 8 Mbps can look very different depending on the codec (H.264, HEVC, AV1), the resolution, the frame rate and how much motion the footage has. The frame rate calculator covers the time side of that.
- Bitrate is not the same as transfer speed. To see how long a file takes to upload or download at your connection speed, use the download time calculator or the bandwidth calculator.
- A bitrate calculator online can't see inside the file. If you want the exact figure, your player's media information panel (for example Codec Information in VLC) reads it from the stream itself.
