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Video file size calculator

Estimate a video's file size from its duration and bitrate.

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Need File size (GB), File size (MB)? The Video file size calculator derives it from Duration (minutes), Bitrate (Mbps) in one step. For instance, with Duration (minutes) = 60 and Bitrate (Mbps) = 8 it returns File size (GB) = 3.516 and File size (MB) = 3,600.

How to use it

  1. Enter your values: Duration (minutes), Bitrate (Mbps).
  2. Read the result instantly: File size (GB), File size (MB).

Frequently asked questions

What does the Video file size calculator actually compute?

It takes Duration (minutes) and Bitrate (Mbps) and derives File size (GB) and File size (MB) from them. The calculation is live as you type, so the result updates on every change.

What information do I need to provide?

2 values: Duration (minutes) and Bitrate (Mbps). Nothing else is required — no account, no file upload.

Can you show a worked example?

With Duration (minutes) = 60 and Bitrate (Mbps) = 8, the calculator returns File size (GB) = 3.516 and File size (MB) = 3,600. Those figures come from running this exact tool, so you can reproduce them by entering the same values.

What happens if I enter larger values?

It moves a lot. Using Duration (minutes) = 120 and Bitrate (Mbps) = 8.8 instead, File size (GB) goes from 3.516 to 7.734 — which is why it is worth testing a few scenarios rather than trusting a single figure.

What does it give for smaller values?

Scaled down to Duration (minutes) = 30 and Bitrate (Mbps) = 7.2, File size (GB) comes out at 1.582. The relationship is worth checking at both ends before you rely on a single result.

When would I actually use this?

Finding out how big a thing will be before you make it: how many gigabytes an hour of footage takes, how long a file needs on the connection you have, how large a photo prints before it goes soft, what bitrate fits the budget you were given.

What is the most common mistake?

Taking the advertised connection speed as the transfer speed. A 100 Mb/s line is megabits, the file is in megabytes, and the eight-fold difference between them is where most download estimates go wrong — before overhead and contention take their own share.

What is the difference between the Video file size calculator and the Audio file size calculator?

Both return File size (MB). What differs is what they ask for: this one wants Bitrate (Mbps), the Audio file size calculator wants Sample rate (kHz) and Bit depth. Use whichever matches the numbers you already have.

Is there a tool for the next step?

Photo File Size Estimator is the closest one after this: Estimate the pixel dimensions and JPEG, RAW and TIFF file sizes from megapixels, aspect and bit depth.

What else is worth having open alongside it?

Video frame count calculator and Paper Size Reference (A4, Letter, ISO 216) — they come up in the same task often enough to be worth a second tab.

Further reading

All guides →
How-toHow to Estimate Video File Size (Bitrate x Duration)Estimate any video's file size before you export. Learn the bitrate-times-duration formula, why you divide by 8, and how resolution and frame rate change the result.ExplainerWhat Is Bitrate? Bits per Second, CBR vs VBRBitrate is how many bits of data a video or audio stream uses each second. Learn how it sets quality and file size, and the difference between constant and variable bitrate.ExplainerScreen Resolutions Explained: 1080p, 1440p, 4KWhat 1080p, 1440p, and 4K really mean. Learn how resolution counts pixels, why total pixels grow so fast, and how aspect ratio ties width to height.ExplainerWhat Are PPI and DPI? Pixel Density for Screen and PrintPPI and DPI both measure density per inch, but one is about screens and the other about print. Learn how to compute pixel density and what Retina really means.ExplainerHow Big Is That Audio File?Uncompressed audio size is exact arithmetic: sample rate × bit depth × channels × seconds ÷ 8. CD audio is 176,400 bytes per second. A 320 kbps MP3, by contrast, is bitrate × duration and does not depend on the sample rate at all — 2,400,000 bytes a minute whether it came from 44.1 or 48 kHz.ExplainerFrame Rates, Timecode, and the Drop-Frame That Drops NothingFrames = duration × rate is trivial until the rate is 29.97. Non-drop timecode then drifts exactly 3.6 seconds an hour. Drop-frame corrects it by skipping 108 frame numbers — the same 108 — but the correction is not perfect: counting every frame shows a residual of 3.6 milliseconds per hour.