Video File Size Estimator
Estimate your video file size from duration, resolution, frame rate and bitrate. Enter the duration and bitrate to estimate the file size in MB and GB.
How to use
- Enter your video duration in minutes and seconds.
- Enter the video bitrate in Mbps (and audio bitrate if you know it).
- Click Estimate File Size to see the size in MB and GB.
About this tool
Use the Video File Size Estimator to estimate your video file size from duration, resolution, frame rate and bitrate. You fill in your duration (minutes), duration (seconds, extra), video bitrate (mbps) and audio bitrate (kbps) and click “Estimate File Size” — the result appears on the same page within seconds. It is free to use, needs no sign-up, and there is nothing to install.
Thumbnails decide whether someone clicks or scrolls past, so the small details matter. The Video File Size Estimator is built for the moment you are finishing a video and need a quick, reliable answer about its thumbnail — before you upload, not after. It suits new creators making their first videos and busy channels publishing every week, because it gives you the result in seconds and lets you move on to the next part of the upload.
Using it takes less than a minute. First, enter your video duration in minutes and seconds. Next, enter the video bitrate in Mbps (and audio bitrate if you know it). Then, click Estimate File Size to see the size in MB and GB.
The result is a single number based on the figures you entered, so it is only as accurate as your inputs. If you type in real figures from YouTube Studio, the answer reflects your channel — if you guess the inputs, the answer is a rough guide at best. One thing worth knowing: for 1080p YouTube uploads, a video bitrate of 8 Mbps is a common starting point, and 45 Mbps for 4K. Treat the figure as an estimate for planning, not a guaranteed outcome — your real results will depend on your audience, niche and timing.
- Double-check your duration (minutes) before you click “Estimate File Size” — a typo or an extra space is the most common cause of a strange result.
- Keep in mind that file size (MB) = bitrate (Mbps) x duration (seconds) / 8.
- Use it on every upload, not just the important ones — thumbnails are the first thing viewers judge.
Frequently asked questions
Is the Video File Size Estimator free?
Yes, it is completely free and needs no sign-up. Enter the duration and bitrate to get an estimate.
How is the file size estimated?
File size (MB) = bitrate (Mbps) x duration (seconds) / 8. This is an estimate — the real file size also depends on the codec and audio bitrate.
What bitrate should I use?
For 1080p YouTube uploads, a video bitrate of 8 Mbps is a common starting point, and 45 Mbps for 4K. Add about 0.3 Mbps for audio.