Free video tool
Video file size calculator
Enter duration and bitrates to estimate the final file size. The result shows decimal MB/GB, storage per minute, and why an actual variable-bitrate export may differ.
About 61.0 MB per minute at 8.128 Mbps combined bitrate. Variable-bitrate output will vary with content.
What the result means
Encoded file size is driven mainly by bitrate and duration, not by resolution alone. A static product walkthrough can compress far more efficiently than fast game footage at the same dimensions. The calculator adds video and audio bitrate, converts bits to bytes, then multiplies by time. Container metadata is small but not zero.
Formula or method
size in MB = duration in seconds × (video Mbps + audio Kbps ÷ 1000) ÷ 8. The result uses decimal megabytes, where 1 GB = 1000 MB.
Boundaries to remember
- Variable-bitrate encoders target visual quality, so the final average bitrate can be above or below your input.
- GIF size behaves differently because GIF is not a modern video codec and often grows quickly with color and frame count.
- Cloud services may count storage in decimal units while operating systems display binary GiB.
Use the result
From calculation to a cleaner recording
Use the average bitrate
For constant-bitrate exports, use the configured number. For variable bitrate, use the encoder's expected average or calculate it from a representative test export.
Add audio even when it looks small
128 Kbps audio is only 0.128 Mbps, but it still adds about 0.96 MB per minute. Long tutorials make that contribution visible.
Test the content, not only the settings
A short sample containing the same cursor motion, scrolling, webcam, and background detail is the best predictor of the real export.
Questions
How large is a 10-minute 1080p video?
Resolution alone is not enough. At 8 Mbps video plus 128 Kbps audio, this calculator estimates about 610 MB for ten minutes, before small container overhead.
Why is my exported file different from the estimate?
Most modern encoders use variable bitrate. Simple frames use fewer bits and detailed motion uses more. Container overhead, additional audio tracks, metadata, and the encoder's rate control also affect the result.
What bitrate should a screen recording use?
There is no single correct bitrate. Text clarity, resolution, frame rate, scrolling, webcam detail, codec, and delivery channel all matter. Export a short representative sample and inspect text and motion at the intended viewing size.
Does lowering frame rate reduce file size?
At the same quality target it often can, because fewer frames need encoding. At a fixed bitrate the file size stays similar and the encoder instead has more bits available per frame.
Does Rekort export MP4 and GIF?
Yes. Rekort exports local MP4 or GIF files with zoom events, backgrounds, webcam, and timeline changes rendered into the result.
Put the answer into the recording.
Rekort records screen, webcam, system audio, and microphone on macOS, then adds auto-zoom, timeline corrections, backgrounds, and local MP4 or GIF export.