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Bitrate is the amount of data a video spends on each second. Here is how it decides file size and quality, what the recommended numbers are, and how to check your own files.
Video bitrate is the amount of data a video uses for each second of playback, usually measured in megabits per second (Mb/s, often written Mbps). A higher bitrate gives the encoder more data to describe each frame, so fine detail and fast movement survive better, and the file grows in step: a 10 Mb/s video takes about 75 MB per minute.
As a guide, YouTube recommends uploading 1080p at 8 Mb/s and 4K at 35–45 Mb/s for standard frame rates, and roughly 1.5 times that at 50 or 60 fps (YouTube Help, checked on 7 November 2026). There is no single “good” bitrate: it depends on resolution, frame rate, codec and how much the picture moves.
This guide explains how bitrate works, compares constant and variable bitrate, and includes a calculator that turns any two of file size, duration and bitrate into the third. To measure a file you already have, open it in the video bitrate checker, which graphs its bitrate over time on your device without uploading it.
File Explorer can show the bitrate stored in a file’s header. These steps work in Windows 10 and Windows 11.
In File Explorer, right-click the video and choose Properties.
Select the Details tab and scroll to the Video heading.
Data rate is the video stream alone; Total bitrate adds the audio. Both are in kilobits per second (kbps): 8,000 kbps is 8 Mb/s. Some formats, MKV in particular, leave these fields blank.
On any device, divide the file size by the duration: size in megabytes × 8 ÷ length in seconds gives the average in Mb/s. The calculator below does the sum for you.
File size is bitrate multiplied by time. Because bitrate is quoted in bits and file sizes in bytes, the one thing to remember is the factor of eight: megabytes = megabits per second × seconds ÷ 8. Fill in any two boxes and the third is worked out for you.
File size: 600 MB
Includes sound in the bitrate. 1 MB = 1,000,000 bytes; 8 bits per byte.
| Situation | Known | Result |
|---|---|---|
| 10 minutes of 1080p at 8 Mb/s | Bitrate and Duration | File size ≈ 600 MB |
| 1 minute of 4K at 45 Mb/s | Bitrate and Duration | File size ≈ 340 MB |
| A 2 GB file lasting 20 minutes | File size and Duration | Bitrate ≈ 13.3 Mb/s on average |
| A 25 MB attachment limit, 60-second clip | File size and Duration | Bitrate ≈ 3.3 Mb/s in total; about 3.2 Mb/s for video after 128 kb/s of audio |
The most widely cited figures are YouTube’s recommended upload settings. They are a sound guide for any H.264 file you plan to upload or share, because they aim for files that survive the platform’s own re-encoding with detail to spare.
| Resolution | SDR, 24–30 fps | SDR, 48–60 fps | HDR, 24–30 fps | HDR, 48–60 fps |
|---|---|---|---|---|
| 8K | 80–160 Mb/s | 120–240 Mb/s | 100–200 Mb/s | 150–300 Mb/s |
| 2160p (4K) | 35–45 Mb/s | 53–68 Mb/s | 44–56 Mb/s | 66–85 Mb/s |
| 1440p | 16 Mb/s | 24 Mb/s | 20 Mb/s | 30 Mb/s |
| 1080p | 8 Mb/s | 12 Mb/s | 10 Mb/s | 15 Mb/s |
| 720p | 5 Mb/s | 7.5 Mb/s | 6.5 Mb/s | 9.5 Mb/s |
| 480p | 2.5 Mb/s | 4 Mb/s | Not supported | Not supported |
| 360p | 1 Mb/s | 1.5 Mb/s | Not supported | Not supported |
For sound, the same page recommends 128 kbps for mono, 384 kbps for stereo and 512 kbps for 5.1, in AAC-LC or Opus at 48 kHz. Audio is a small part of most files: 384 kbps is under 5 per cent of an 8 Mb/s 1080p video.
These are figures for uploading. What viewers receive after a platform re-encodes is lower, and HEVC or AV1 files can look as good as these H.264 targets at a lower bitrate. Treat the numbers as a floor for uploads rather than a target for every file.
Dividing bitrate by the number of pixels shown per second gives a rough measure of how generously a video is encoded. Larger frames share more detail between neighbouring pixels, so they need fewer bits per pixel for the same look.
| Video | Bitrate | Pixels per second | Bits per pixel |
|---|---|---|---|
| 720p at 30 fps | 5 Mb/s | 27.6 million | 0.18 |
| 1080p at 30 fps | 8 Mb/s | 62.2 million | 0.13 |
| 1080p at 60 fps | 12 Mb/s | 124.4 million | 0.10 |
| 4K at 30 fps | 40 Mb/s | 248.8 million | 0.16 |
An encoder can spend its bits evenly or follow the picture. Which it does changes how a file behaves when streamed and how its bitrate looks when you measure it.
Most tools report a single number, the average over the whole file. The peaks matter too: a 20 Mb/s average file may spike to 60 Mb/s on a burst of confetti or a fast pan, and a slow card, network or old TV may stutter there even though it copes with the average. Key frames, the complete pictures a codec stores every second or two, also stand out as small spikes. The bitrate graph in the bitrate checker shows all of this for your file, measured from packet sizes without decoding.
Phone videos are often several times the bitrates in the table above. A phone encodes in real time with a hardware encoder that has a fraction of a second to decide how to compress each frame, so it can’t search for savings the way a slow desktop encoder can, and it plays safe by spending more bits. Phone recordings commonly land somewhere between about 10 and 100 Mb/s depending on resolution, frame rate and codec; open one of yours in the bitrate checker to see where it sits.
Professional formats go much further. Apple says ProRes recordings on Pro iPhones can be up to 30 times larger than HEVC, because ProRes compresses each frame on its own for easy editing. At the other end, an HEVC recording needs a noticeably lower bitrate than H.264 for similar quality; the HEVC vs H.264 comparison explains why.
Up to a point. Raising the bitrate of a starved encode makes a visible difference; raising it further makes a smaller one, until extra bits buy nothing you can see. Several things limit what bitrate can do:
To judge your own files, compare bitrate with resolution in the resolution checker and frame rate in the frame rate checker. A 4K file at 5 Mb/s, for example, has almost certainly been squeezed hard.
YouTube recommends 8 Mb/s for 1080p at 24–30 fps and 12 Mb/s at 48–60 fps for SDR uploads in H.264 (checked on 7 November 2026). HEVC can look similar at less; screen recordings with little movement can use much less.
YouTube’s recommendation is 35–45 Mb/s for 4K SDR at 24–30 fps and 53–68 Mb/s at 48–60 fps, with higher figures for HDR. Phone recordings are often higher still because real-time encoders are less efficient.
Only up to a point, and only within the same codec and source. Beyond what the content needs, extra bitrate makes a bigger file without a visible improvement, and it can never add back detail the source didn’t have.
Mbps is megabits per second and MB/s is megabytes per second. There are 8 bits in a byte, so 80 Mbps equals 10 MB/s.
Multiply the bitrate in Mb/s by the length in seconds and divide by 8 to get megabytes. Ten minutes at 8 Mb/s is 8 × 600 ÷ 8 = 600 MB. The calculator on this page does it for you.
With variable bitrate or constant-quality encoding, the setting is a target or a ceiling, not an exact figure. Simple footage often comes in below it, and the container adds a little overhead on top.
Yes. Open it in the video bitrate checker: it reads the file on your device and shows the video and audio bitrates, a graph of how the bitrate changes over time, and the overall bitrate in its full report.