Local bitrate math

Bitrate Calculator

Calculate the bitrate needed to hit a target video file size for a given duration.

Target size workspace

Enter file size, duration, and audio bitrate to estimate video bitrate.

Target file size

Size unit

Duration

Duration unit

Audio bitrate Kbps

Result

Estimated total bitrate: 1.33 Mbps. Video bitrate after 128 Kbps audio: 1.21 Mbps.

Total

1.33 Mbps

Video

1.21 Mbps

Audio

128 Kbps

How it works

1 Set the target file size.
2 Enter the video duration and expected audio bitrate.
3 Copy the estimated total and video-only bitrate.

FAQ

Are calculations sent to a server?

No. These calculators run locally in your browser and do not upload files or inputs.

Are the results exact?

They are planning estimates. Real exports can vary because codecs, motion, audio, metadata, and platform re-encoding all affect final size and quality.

Why subtract audio bitrate?

Audio uses part of the total bitrate budget, so the calculator shows a video-only value after reserving space for audio.

Want professional polish?

These calculators help you plan exports. Aufzeichna's desktop app helps you create the polished recording with cinematic zoom, smooth cursor motion, and export control.

Check out the desktop app