Video Bitrate & File Size Calculator
Work out how big a video will be at a given bitrate, what bitrate you need to squeeze a clip under an upload limit, or how long a video can be for a given size — with YouTube's recommended bitrates built in.
MP4/MKV headers and indexes — usually 1–3%.
Estimated file size
641.4 MB
611.7 MiB as shown by Windows · total 8.38 Mbps for 10 min 0 s
YouTube recommended upload bitrates
| Resolution | 24–30 fps | 48–60 fps |
|---|---|---|
| 8K (4320p) | ||
| 4K (2160p) | ||
| 1440p (2K) | ||
| 1080p | ||
| 720p | ||
| 480p | ||
| 360p |
Click a value to use it (ranges use the midpoint). Audio: 128 kbps mono, 384 kbps stereo, 512 kbps 5.1.
Data last updated:
Bitrate, duration and file size — solve for any one
A video’s file size is determined by just two things: its bitrate (how many bits are used per second) and its length. Resolution, frame rate and codec affect how good the video looks at a given bitrate, but not how big the file is. That makes file sizes easy to predict — and it means you can work backwards to choose the right bitrate for an upload limit, a storage budget or a streaming platform.
How to use the calculator
- Choose what to calculate: the file size of a video, the bitrate needed to fit a target size, or the maximum duration that fits in a size.
- Enter the duration in hours, minutes and seconds.
- Enter the video bitrate (or click a YouTube recommendation), plus the audio bitrate.
- For a target size, enter the limit or tap a preset such as 8 MB or 25 MB.
- Adjust container overhead if you know your format adds more or less than the default 2%.
The formulas
Bitrates are measured in bits per second, and file sizes in bytes, which are 8 bits each. So:
- File size (bytes) = (video bitrate + audio bitrate) × duration in seconds ÷ 8 × (1 + overhead)
- Total bitrate = file size × 8 ÷ duration ÷ (1 + overhead), and video bitrate = total − audio
- Maximum duration = file size × 8 ÷ total bitrate ÷ (1 + overhead)
Example: a 10-minute 1080p video at YouTube’s recommended 8 Mbps with 384 kbps stereo audio comes to about 629 MB, or roughly 640 MB with 2% container overhead. Sizes here use decimal units (1 MB = 1,000,000 bytes), as file hosts and upload limits usually do; Windows reports binary units (MiB), which look about 5% smaller, so both are shown.
YouTube’s recommended bitrates
The table under the calculator lists YouTube’s published upload recommendations for SDR and HDR video at standard (24–30 fps) and high (48–60 fps) frame rates. Uploading at or above these rates gives YouTube a good source to re-encode from; going much higher mainly increases upload time. The figures were last checked on 2026-09-27.
Hitting an exact target size
Encoders using constant quality or single-pass variable bitrate can’t guarantee a size. To land under a hard limit, encode with two-pass mode at the video bitrate this tool suggests — in HandBrake choose “Avg Bitrate” with “Multi-Pass Encoding”, or in FFmpeg use -b:v with -pass 1 and -pass 2. Leave a little headroom, as some encoders overshoot slightly. If the required bitrate is very low, reduce the resolution: a sharp 720p video looks better than a blocky 1080p one.
Need to convert a file to a widely compatible MP4 first? Use Video to MP4. For frame-accurate durations, see the Timecode Calculator, and check export dimensions with the Aspect Ratio Calculator.
Frequently asked questions
How do I calculate video file size from bitrate?
File size = total bitrate × duration ÷ 8. For example, 8 Mbps video plus 0.384 Mbps audio for 10 minutes (600 s) is 8.384 × 600 ÷ 8 = 628.8 MB, plus a little container overhead.
What bitrate do I need to fit a video under 25 MB?
Divide the size in bits by the duration. 25 MB is 200 megabits, so a 60-second clip can use about 3.3 Mbps in total — roughly 3.2 Mbps for video if audio uses 128 kbps. Use the 'Bitrate for a target size' mode for exact numbers.
What bitrate does YouTube recommend for 1080p?
YouTube recommends 8 Mbps for 1080p SDR uploads at 24–30 fps and 12 Mbps at 48–60 fps, with 384 kbps stereo audio. The full table is below the calculator.
Why is my file size different from the calculation?
Most encoders use variable bitrate (VBR), so the actual average can differ from the target. Container overhead, subtitles and extra audio tracks add a little more. Also, Windows shows sizes in binary units (MiB/GiB), which look about 5–7% smaller than decimal MB/GB.
Is a higher bitrate always better?
Only up to a point. Beyond what the resolution and codec need, extra bitrate adds file size without visible improvement. Newer codecs like H.265/HEVC and AV1 reach similar quality at lower bitrates than H.264.