Screen Recording File Size Calculator: Estimate MB, GB, and Recording Time

Estimate screen-recording storage by multiplying the displayed MB per minute by the planned duration. The result is a planning number, not a fixed target: motion, video playback, noise, resolution, FPS, and compression change how much data the encoder needs.

What “estimated MB per minute” means

The estimate describes an expected rate under the selected source and quality settings. It is not a requested final file size and not a promise. A nearly static slide can compress much more efficiently than a full-screen video, game, or rapidly scrolling page.

For a realistic plan, record one minute containing the same kind of motion and audio as the real session. Compare the actual file size with the on-screen estimate and adjust your safety margin.

MB per minute is clearer than a target file size

A target such as “make this recording 500 MB” is ambiguous before the duration is known. A rate estimate explains the relationship: 25 MB per minute suggests about 250 MB for ten minutes or 1,500 MB for one hour. The calculator applies that relationship directly.

Some encoders show megabits per second (Mbps) instead. To convert a constant bitrate approximately, multiply Mbps by 7.5 to get MB per minute. For example, 4 Mbps is about 30 MB per minute. Variable video compression means the actual Free Screencast result can still move above or below a simple bitrate calculation.

Example calculations

Why actual size changes

• Motion: games and video change more pixels than documents and slides.
• Capture area: a full high-resolution display contains more information than one small window.
• Frame rate: 60 FPS produces more motion samples than 30 FPS.
• Compression: stronger compression generally reduces size but can soften fine text.
• Audio: microphone and system audio add data, though video is usually the larger share.
• Container and codec behavior: MP4, MKV, WebM, MOV, WMV, and AVI do not all use identical encoding paths.

Plan free disk space safely

1. Calculate the expected total.
2. Add at least 20–30% for content variation.
3. Keep extra space for snapshots, a trimmed copy, GIF export, and temporary finalization.
4. For an important long recording, make a representative one-minute test and extrapolate from the actual file.

Do not start a critical session with only the calculated minimum available. Windows and other applications also need working space.

Plan a long or scheduled recording

For an unattended job, calculate storage from the exact scheduled duration, verify the output drive, connect power, and prevent sleep. Run a rehearsal using the same source and settings. A one-minute test can expose an estimate that is unrealistic for fast motion, while a ten-minute test gives a stronger basis for a multi-hour plan.

Automatic stop is measured in minutes and limits the maximum recording duration. Leave it off when you intend to stop manually, but then plan for the longest reasonable session rather than the shortest expected one.

Account for copies and exports

Quick trim can create a new copy while the original remains. GIF export and snapshots also use additional space. If you need to preserve the original until approval, budget for both source and final files instead of assuming the trim will replace the recording.

Reduce the estimate without blurring text

Capture one window or a focused region, use 30 FPS for ordinary tutorials, remove idle time, and increase compression gradually. Compare a short moving sample at the actual viewing size. See the complete screen-recording file-size guide for the quality checklist.