Video File Size Calculator
Estimate video file size from bitrate and duration, or get a recommended bitrate from resolution and frame rate using a bits-per-pixel target.
Result
- Video bitrate8 Mbps
- Audio bitrate192 kbps
- Total bitrate8.192 Mbps
- Duration10 min (600 s)
- File size585.9 MiB (614.4 MB)
Step-by-step
- Total bitrate = video 8 Mbps + audio 192 kbps = 8.192 Mbps.
- File size = bitrate × duration ÷ 8 = 8.192 Mbps × 600 s ÷ 8 = 614,400,000 bytes.
- That is 585.9 MiB (614.4 MB).
How to use this calculator
- Pick a mode: file size from bitrate, or recommended bitrate from resolution.
- For file size, enter the video and audio bitrates and the duration.
- For bitrate, enter width, height, frame rate, and a bits-per-pixel target.
- Read the file size (or recommended bitrate) and the breakdown.
About this calculator
A video file's size is governed by its bitrate — the amount of data used per second — and its duration. This calculator works in two directions. In file-size mode it multiplies the total bitrate (video plus audio) by the running time and divides by eight to convert bits to bytes, giving the size of the finished file. In bitrate mode it estimates a sensible target bitrate for a given resolution and frame rate using a bits-per-pixel figure, which encodes how aggressively the codec compresses: H.264 at good quality is around 0.10 bits per pixel, while newer codecs like HEVC and AV1 reach similar quality at roughly half that. The file-size calculation is exact for a constant bitrate; the recommended-bitrate figure is a rule of thumb, since real encoders vary the bitrate with scene complexity.
How it works — the formula
Size = (Video Mbps + Audio kbps/1000) × Duration(s) × 10⁶ ÷ 8
Recommended bitrate ≈ Width × Height × FPS × bits-per-pixelFile size is total bitrate times duration in bits, converted to bytes. The recommended bitrate scales a per-pixel quality target by how many pixels are encoded per second.
Worked examples
- Inputs:
- mode=size, videoBitrate=8, audioBitrate=0, minutes=10
- Output:
- 8e6 × 600 ÷ 8 = 600 MB (572 MiB)
- Inputs:
- mode=size, videoBitrate=5, audioBitrate=192, minutes=60
- Output:
- ≈ 2.34 GB
- Inputs:
- mode=bitrate, width=1920, height=1080, fps=30, bpp=0.1
- Output:
- 6.22 Mbps
Limitations
- Recommended-bitrate mode is a bits-per-pixel heuristic, not a codec model.
- Assumes constant average bitrate; ignores container overhead.
- Codec choice (H.264 vs HEVC/AV1) hugely changes the quality-per-bit.
File size is exact for a given bitrate; bitrate recommendations are starting points only.