Video Bitrate Calculator
Calculate the video bitrate needed to hit a target file size. Planning numbers for Handbrake or desktop FFmpeg — this page does not encode video in the browser.
Video Compression Calculator
This page is a bitrate calculator. Enter duration and a target file size to get the average video bitrate. It does not load FFmpeg.wasm or encode a video file — use the number in Handbrake or desktop FFmpeg.
Example planning sizes — not verified live platform caps. Confirm the current limit with the destination.
Deducted from the target size so MP4/MOV muxing does not overshoot. 0% uses the full budget.
Required Video Bitrate
How to use this setting in Handbrake:
- Go to the Video tab.
- Select Avg Bitrate (kbps).
- Enter XXXX.
- Check 2-pass encoding for best results.
What is a video bitrate calculator?
A video bitrate calculator turns a target file size and a clip duration into the average video bitrate an encoder should aim for. This page does that math in your tab. It does not load FFmpeg.wasm, pick a video file, or re-encode anything.
Video file size is mostly bitrate × duration. Lower bitrate means a smaller file and, past a point, visible quality loss. If you need a clip to land near a size budget, calculate the bitrate here, then encode in Handbrake or desktop FFmpeg. Tool inputs stay in the browser.
How to Calculate a Target Video Bitrate
- 1 Enter the video duration.
Type the length of the clip in minutes and seconds.
- 2 Set a target file size.
Enter a size in MB, or pick an example planning size. Platform upload limits change — confirm the destination's current cap before you encode.
- 3 Adjust audio bitrate and overhead.
Set the audio bitrate you plan to use. Optionally reserve container overhead so MP4/MOV muxing is less likely to overshoot the budget.
- 4 Use the bitrate in a desktop encoder.
Copy the required video bitrate into Handbrake (Avg Bitrate) or desktop FFmpeg. This page does not encode or download a video file.
Who Is This For?
Creators planning a Handbrake or FFmpeg encode to fit a size budget before they wait on a long render.
Developers sizing demo videos and screen recordings so documentation and landing pages stay light.
Anyone who wants the bitrate math first. This page does not encode video in the browser and does not replace a desktop compressor.
Key Benefits
No video file is selected or uploaded. Tool inputs stay in the browser.
No subscription, no account, no watermarks. The page does math — it does not encode files, so there is no upload cap to advertise.
Open the page and enter duration and a target size. Nothing to install.
Optional container overhead and bits-per-pixel are planning numbers. Encode with Handbrake or desktop FFmpeg — this tab does not load FFmpeg.wasm.
Common Video Compression Mistakes
- ✗Treating example planning sizes as verified platform caps — Discord, email, and X limits change; confirm the current limit with the destination.
- ✗Setting the bitrate too low for the resolution — a 1080p encode at a very low bitrate looks blocky; match bitrate to resolution or reduce resolution to match the budget.
- ✗Re-compressing an already compressed video — each lossy pass degrades quality; encode from the original high-quality source when you can.
- ✗Expecting this page to encode a file — there is no FFmpeg.wasm compressor here; use a desktop encoder after you have the bitrate.
For related media editing, use our Image Resizer to optimize thumbnail images, or trim audio with the Audio Trimmer.
For technical documentation on video codecs, container formats, and bitrate recommendations, see the MDN Web Docs: Video codecs guide.
The Math Behind Video File Sizes
Video file size is determined by two factors: total runtime and total bitrate (data per second). Resolution and frame rate influence visual quality, but they do not override the mathematical ceiling set by your bitrate.
// The Core Calculation
Total Kilobits = Target Megabytes × 8192
Total Bitrate = Total Kilobits ÷ Duration in Seconds
Video Bitrate = Total Bitrate − Audio Bitrate
For example, to hit exactly 25MB in 2 minutes: (25 × 8192) ÷ 120 = 1,707 kbps total. Subtract ~128 kbps for audio = ~1,579 kbps video bitrate. Use 2-pass encoding in Handbrake or desktop FFmpeg with this target bitrate. Container overhead can still push the file slightly over — that is what the overhead slider is for.
Common Use Cases
Social media upload planning
Calculate a bitrate for a size budget before you encode. Confirm the destination's current upload cap — those numbers change and are not verified here.
Chat and email size budgets
Use an example planning size such as 25MB, then encode in Handbrake. Confirm the live limit with Discord, email, or whatever destination you actually use.
Documentation and landing page videos
Plan a bitrate so product demos and explainer clips stay small enough to host yourself after you encode them on your machine.
Avoiding a wasted encode
Get the target bitrate first so you are not guessing settings and re-rendering a long clip three times.
Frequently Asked Questions
What does this video bitrate calculator do? ▼
This page calculates the average video bitrate needed to hit a target file size from duration, audio bitrate, and optional container overhead. It does not load FFmpeg.wasm or re-encode a video in this tab. Use the number in a desktop encoder such as Handbrake or FFmpeg.
Does this tool compress video in the browser? ▼
No. There is no file picker and no encoder. Enter duration and a target size to get a bitrate. Tool inputs stay in the browser.
Is this calculator free? ▼
Yes. This Video Bitrate Calculator is free to use now — ads are not live yet — with no account required. The math runs in this tab. The site uses aggregate Google Analytics.
How do I use the bitrate in Handbrake or FFmpeg? ▼
In Handbrake: Video tab → Avg Bitrate (kbps) → enter the calculated value → 2-pass encoding if you want a closer size match. Desktop FFmpeg can use the same average bitrate. This page does not run those tools.
Why might the output file still miss the target size? ▼
Container overhead, audio bitrate, and encoder behavior all affect size. Use the overhead slider as a planning buffer. Two-pass encoding usually lands closer than a single pass. The calculator is arithmetic, not a guarantee.
What are the Discord, email, and X size buttons? ▼
They are example planning sizes, not verified live platform caps. Upload limits change. Confirm the current limit with the destination before you encode.
This tool is provided for informational and educational purposes only. Results are not a substitute for professional advice.
Free Tools Alert
Get new tools, templates, and calculators in your inbox. No fake subscriber counts.
No spam. One-click unsubscribe.