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Video compression calculator

To make a video fit a size limit, you need the right bitrate. Enter the limit and the video length; get the bitrate, a sensible resolution, and copy-paste settings for free tools.

Video bitrate:

Total (video + audio):

Suggested max resolution:

FFmpeg (two-pass, most accurate)

HandBrake


Reverse: how big will my video be?
The math
File size = bitrate × duration. So the bitrate that fits is size in bits ÷ seconds, minus the audio bitrate. We subtract about 1.5% for the MP4 container and your safety margin, because encoders overshoot slightly. Two-pass encoding lands closest to the target.


Why a resolution suggestion?
Squeezing 1080p into a low bitrate gives blocky video. Lower resolution at the same bitrate usually looks better. We use rule-of-thumb “bits per pixel” values (about 0.07 for H.264, 0.045 for H.265) – a starting point, not a guarantee. If the result looks bad, trim the clip: halving the length doubles the bitrate you can use.


Current size limits (checked 2026-11-05)
  • Discord: 20 MB without Nitro, 50 MB with Nitro Basic, up to 1 GB with Nitro (Discord FAQ, updated Sept 2026).
  • Gmail: 25 MB for personal accounts; bigger files become a Google Drive link (Gmail Help).
  • Outlook.com: 25 MB per message including text; OneDrive links up to 2 GB (Microsoft Support).


Which app to compress with
Use the numbers above in any encoder. HandBrake and FFmpeg are free. If you prefer a point-and-click app with batch compression, paid converters exist – try the free trial first and check its limits.
Desktop and paid alternatives
Free options first. Facts come from each official page on the date shown.
Free, open source
HandBrake
  • Converts video from nearly any format to modern codecs (H.264, H.265, AV1)
  • Windows, Mac and Linux
  • Has an Avg Bitrate + multi-pass mode that hits a target size
Source: official page, checked 2026-11-05. Prices and limits change – confirm before buying.
Visit HandBrake →
Free, open source
FFmpeg
  • Command-line converter used inside many video apps
  • Exact control over bitrate, resolution and codecs
  • No graphical interface
Source: official page, checked 2026-11-05. Prices and limits change – confirm before buying.
Visit FFmpeg →
Wondershare UniConverter
  • Graphical converter + compressor with batch processing and GPU acceleration
  • Official FAQ: the trial converts only 1/3 of a video's length
  • Official store listed a Yearly Plan at US$45.99/yr (auto-renews) on the date checked
Source: official page, checked 2026-11-05 · official pricing. Prices and limits change – confirm before buying.
Visit Wondershare UniConverter →
Questions
Why is my file still slightly too big?
Raise the safety margin to 8–10% or use two-pass mode. Single-pass and hardware encoders overshoot more.
MB or MiB?
Most apps and services use MB = 1,000,000 bytes. If a limit is in MiB (1,048,576 bytes), choose MiB.
Can this page compress the video itself?
No. Browser-based video encoding is slow and memory-hungry; the free desktop tools below are faster and better. This page gives you the exact settings.
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