Short answer: video file size ≈ (video bitrate + audio bitrate) × duration ÷ 8. Enter your numbers below, or tap a screen-recording preset, and the estimate updates instantly. Nothing is uploaded; it's arithmetic, in your browser.
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Estimate for constant bitrate; variable-bitrate encoders land near this for screen content.
How the math works
Bitrate is bits per second. Multiply by seconds, divide by eight for bytes: a 5-minute 1080p demo at 8 Mbps video + 128 kbps audio is (8,000,000 + 128,000) × 300 ÷ 8 ≈ 305 MB. Screen recordings compress well because most pixels don't change between frames, which is why 2.5 Mbps is watchable for slides but text-heavy demos deserve 8 Mbps or more (see why recordings look blurry).
Picking a bitrate for screen recordings
- Slides / big UI: 2.5–5 Mbps at 1080p is fine.
- Code, terminals, small text: 8–18 Mbps, text shimmer is bitrate starvation.
- 4K masters for YouTube: 35–45 Mbps so the platform's re-encode has headroom.
Recording the video too?
Girato records your screen and auto-edits cinematic zooms from your clicks, free to try in the browser.
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