Video Bitrate Calculator

How to calculate a bitrate budget

1. Enter a positive target size and choose MB, MiB, GB or GiB. Enter duration as seconds, MM:SS or HH:MM:SS. For example, 90 and 1:30 both mean 90 seconds.
2. Open More options to subtract the combined audio bitrate in kbps or keep a chosen percentage of the target size aside. No audio rate or allowance is assumed for you.
3. Read the whole-kbps budget and its label. Without audio subtraction it is a combined-stream budget, not a video-only setting. The number is rounded down; encode and measure the actual output.

File size, audio and average bitrate

Bitrate is bits per second, while file size counts bytes. One byte is 8 bits; kbps means 1,000 bits per second. MB and GB are decimal units, while MiB and GiB use binary byte counts.

Available total kbps = target bytes × 8 × (1 − allowance percent ÷ 100) ÷ (duration seconds × 1,000). Subtract the combined audio kbps only when audio will use part of that budget.

The allowance keeps a chosen share of the whole target aside before audio subtraction. It is not a measured container overhead or a guarantee. If audio uses all the available budget, no video bitrate remains.

The result is an average-bitrate budget, not a CRF/RF value or quality score. Constant-quality encoding can produce different sizes for different content. Codec behavior, metadata and additional streams can change actual output size.

Worked bitrate examples

100 MB over 5 minutes gives a total budget of 2,666 kbps after rounding down. The same numeric size in MiB gives 2,796 kbps because 100 MiB contains more bytes.

200 MB over 10 minutes with 128 kbps audio leaves a video budget of 2,538 kbps. Reserving 2% of that target first leaves 2,485 kbps for video: 4 MB is reserved, leaving 196 MB before subtracting audio. These are examples, not recommended defaults.

1.001 MB over 1 second has an exact total budget of 8,008 kbps. The calculator preserves decimal input before flooring, rather than losing one kbps to intermediate floating-point rounding.

An encoding budget, not a size guarantee

Supported targets are positive and at most 1 TiB; duration is 0.001 seconds to 168 hours. Size accepts six fractional places, audio three and allowance two. Point or comma decimals are accepted, but grouping and scientific notation are not.

No quality, resolution, codec or upload-platform limit is inferred. Audio must include all tracks you want to subtract. Actual output, container data and encoder behavior must be checked; a positive budget below 1 kbps is reported without suggesting zero.

Your entries

The arithmetic runs in your browser. This tool adds no input upload, saved record or input-bearing URL. Existing website consent, analytics and network services remain separate.