How to Choose the Right Streaming Bitrate for OBS

Every upload limit is really a bitrate limit wearing a disguise. Fitting a video into a size cap means working backwards: the size and the duration are fixed, so the bitrate is whatever is left over.

What the Streaming Bitrate Calculator does

Takes a target file size and a duration and returns the video bitrate that lands inside it, after subtracting the audio track and container overhead.

The relationship is simply size = bitrate × duration, which is why the same 25 MB limit is generous for a 30-second clip and impossible for an hour.

Open the Streaming Bitrate Calculator and follow the settings and checks below.

Inputs

Setting	What it means
Video length	In minutes, from 0.1
Target file size	In MB, from 1
Audio bitrate	Subtracted from the budget — default 128 kbps
Returns	The video bitrate that fits
Core relationship	Size = bitrate × duration
Halve the duration	Doubles the bitrate you can afford
Halve the bitrate	Halves the file size
Use with	OBS, ffmpeg, or any encoder that takes a target rate

How to use it

1. Enter the duration and the size you must fit inside.
2. Set the audio bitrate you intend to use — it comes out of the same budget.
3. Take the video bitrate to your encoder.

A practical quality check

If the answer comes back under about 1000 kbps for 1080p, do not use it — drop the resolution instead. A frame that large starved of data looks blocky in exactly the places viewers look. The same bitrate at 720p, or 480p for a very tight budget, produces a visibly better result.

Common questions

The bitrate it gives me looks impossibly low.

Then the target is too small for the duration, and no encoder setting fixes that. Your options are a shorter clip, a lower resolution, or a bigger limit. Trimming is usually the least painful, because it removes data at full quality rather than degrading all of it.

Why does audio come out of the budget?

Because the limit applies to the finished file, and the audio track is inside it. At 128 kbps audio takes about 1 MB per minute — on a 25 MB cap for a ten-minute video that is 40% of the space.

Should I use this or the Video Compressor?

The compressor does this arithmetic and the encoding in one step. This tool is for when you are configuring something else — OBS, a hardware encoder, an ffmpeg command — and just need the number.

Is a higher bitrate always better?

Only up to the point where the frame can use it. Beyond that you are storing detail no one can see, and running into upload limits for nothing. The resolution ladder in the OBS assistant shows roughly where that point is.

Useful next tools

• Compress Video — Shrink any video in your browser — pick a quality level or a size to fit.
• Obs Settings Assistant — Recommended bitrate and encoder settings for your setup.
• Upload Time — How long a file will take on your connection.
• Resize Video — Resize a video to 1080p, 720p, 480p or 360p, keeping aspect.

Vootkit provides a browser tool and educational guidance, not a guarantee that every browser, device or third-party platform will accept every file. Platform specifications can change, so verify important publishing requirements with the destination service.