Formula
S = R × T ÷ 8 · R = S × 8 ÷ T · T = S × 8 ÷ R
Total bits equal average bits per second multiplied by seconds. Divide or multiply by eight when moving between bits and bytes.
Network & data
● Runs locallyBitrate, Size & Duration
Find one missing media quantity from average bitrate, file size and duration. Leave exactly one value empty; CalcFlow never guesses which populated value should be replaced and shows the inverse formula used.
Example values
Calculated missing value
Assumptions
- Bitrate is the total average across all streams and container overhead.
- No codec quality or compression recommendation is inferred.
Bitrate means total average bitrate in V1. Variable bitrate media remains an estimate.
Formula review
Formula v1.0.0
Reviewed 2026-08-03
CalcFlow engineering review
Bitrate, Size & Duration: Worked example
8 Mbps for 10 minutes produces 8,000,000 × 600 ÷ 8 = 600,000,000 bytes, or 600 MB.
Frequently asked questions
Which value should be empty?
Leave exactly one of file size, bitrate or duration empty. That is the value CalcFlow solves.
Does variable bitrate change the result?
The result is an estimate when the entered bitrate is an average. Peaks and container overhead may change an actual file.
Does the calculator separate audio and video?
No. V1 expects a combined total average bitrate.