How big is a 10-minute video at 1080p?

At a video bitrate of 8 Mbps with 384 kbps audio, ten minutes comes to roughly 630 MB. The figure scales directly with bitrate: dropping to 5 Mbps gives about 400 MB for the same length.

Why does my actual file differ from the estimate?

Because nearly all modern encoding uses variable bitrate, so the data rate rises and falls with visual complexity instead of holding steady. Static footage comes out under the estimate, while fast motion can land slightly over.

How do I shrink a video to fit a size limit?

Use this calculator's reverse mode to find the highest bitrate that fits, then re-export at that rate. Lowering resolution helps too, but reducing bitrate at the same resolution usually looks better than dropping the resolution itself.

YouTube Tools

Video File Size Calculator

Enter bitrate and duration to estimate the file size, or set a size limit to find the bitrate that fits.

Minutes Seconds Video bitrate (Mbps) Audio bitrate (kbps)

Estimated size —

Audio share —

REVERSE — FIT A SIZE LIMIT

Size limit (MB)

Max video bitrate —

SIZE MB = ((VIDEO + AUDIO) Mbps × SECONDS) ÷ 8

What this is

A video file size calculator converts bitrate and duration into an estimated file size, using a direct relationship: bitrate is data per second, so multiplying it by the number of seconds gives the total. It earns its keep when a size limit has to be met — an email attachment, an upload cap, a storage quota — because it also runs backwards to find the highest bitrate that still fits.

The formula

size (MB) = ((video Mbps + audio Mbps) × duration in seconds) ÷ 8

The division by 8 converts megabits into megabytes.
audio Mbps — the audio bitrate in kbps divided by 1,000.
Reversed: bitrate = (size in MB × 8) ÷ duration in seconds.

How it works

Bitrate is measured in megabits per second while file size is measured in megabytes, and a byte is eight bits. That division by eight is the step most often forgotten, and forgetting it produces an estimate eight times too large.

Audio bitrate adds to the total and has to be counted separately, because audio is encoded on its own. On a long video with a low video bitrate, audio can take a meaningful share — 384 kbps over an hour is about 170 MB by itself.

The result is an estimate, not an exact figure. Variable bitrate encoding lets the data rate rise and fall with visual complexity, so a video with many static scenes comes out smaller than predicted, and one full of fast motion slightly larger.

How to use it

Enter the duration Enter the video's length in minutes and seconds.
Enter video and audio bitrate Use the figures from your editor's export settings.
Or set a size limit Enter a size cap to see the highest video bitrate that still fits inside it.

Common questions

How big is a 10-minute video at 1080p?: At a video bitrate of 8 Mbps with 384 kbps audio, ten minutes comes to roughly 630 MB. The figure scales directly with bitrate: dropping to 5 Mbps gives about 400 MB for the same length.
Why does my actual file differ from the estimate?: Because nearly all modern encoding uses variable bitrate, so the data rate rises and falls with visual complexity instead of holding steady. Static footage comes out under the estimate, while fast motion can land slightly over.
How do I shrink a video to fit a size limit?: Use this calculator's reverse mode to find the highest bitrate that fits, then re-export at that rate. Lowering resolution helps too, but reducing bitrate at the same resolution usually looks better than dropping the resolution itself.

Notes

An estimate, not an exact figure — variable bitrate encoding makes real results vary.