🎬 Video Bitrate: Calculator

Find the video bitrate needed to hit a target export file size.

MB
seconds
kbps
TARGET VIDEO BITRATE
0 kbps
set this as your video (not audio) export bitrate
Total Bitrate Needed
0 kbps
Audio Bitrate
0 kbps
Duration (mm:ss)
0:00
Target File Size
0 MB
Total Bitrate = Size (MB) × 8 × 1024 ÷ Duration (s); Video Bitrate = Total − Audio

How the Video Bitrate Calculator Works

When exporting or compressing a video to hit a specific file size — for an upload limit, a disc, or limited storage — you need to know what total bitrate to encode at. This calculator works backward from your target file size and duration to find the total bitrate needed, then subtracts your audio track's bitrate to give you the correct video bitrate setting for your encoder.

Total Bitrate Needed (kbps) = Target File Size (MB) × 8 × 1024 ÷ Duration (s)
Video Bitrate (kbps) = Total Bitrate Needed − Audio Bitrate

Why Subtract the Audio Bitrate?

A video file's total data rate is shared between its video stream and its audio stream. If you set your video encoder's bitrate to the full total bitrate without accounting for audio, your finished file will end up larger than your target because the audio track adds its own data on top. Subtracting a typical audio bitrate (128 kbps is a common default for stereo AAC or MP3 audio) up front ensures the combined video + audio streams land at your intended file size.

Choosing a Target File Size

Common target sizes include platform upload limits (some messaging apps cap video uploads around 16-100 MB), email attachment limits, or simply fitting multiple clips onto a USB drive or disc. Once you know your target size and the video's duration, this calculator gives you the exact video bitrate to plug into your export or compression software (such as HandBrake, FFmpeg, or a video editor's export settings) to reliably hit that size.

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❓ Frequently Asked Questions

How do I use this to compress a video to a specific file size?
Enter your target file size in MB and the video's duration in seconds. The calculator gives you the total bitrate needed, then subtracts your audio bitrate to show the exact video bitrate to set in your export or compression software.
What audio bitrate should I use in the calculation?
128 kbps is a common default for stereo audio using AAC or MP3 encoding and works well for most videos. If your source audio uses a different bitrate, enter that value instead for a more accurate result.
Why might my exported file still be slightly different from my target size?
Most modern encoders use variable bitrate (VBR) rather than a perfectly constant bitrate, and container overhead (file headers, metadata) adds a small amount of extra size, so real-world results are usually close to, but not exactly, the calculated target.
Can I use this for audio-only files, like podcasts?
This calculator is designed for video with an audio track. For audio-only files, use the dedicated Audio Bitrate Calculator, which applies the same underlying math without the extra audio-bitrate subtraction step.
What happens if the audio bitrate is higher than the total bitrate needed?
If your target file size is very small relative to duration, the audio track alone might exceed your available bitrate budget. In that case, this calculator floors the video bitrate at 0 kbps and you'll need to increase your target file size, shorten the duration, or lower the audio bitrate.

🏆 About This Tool — Accuracy & Trust

🔒 Data Privacy: All calculations run entirely within your browser using JavaScript. Nothing you enter here is ever transmitted to our servers, stored, sold, or shared.

📐 Accuracy Note: This tool uses standard, widely published formulas and guidelines. Results are estimates for informational purposes; for financial, medical, or engineering decisions, consult a licensed professional.

📅 Last Updated: September 2026.