Screen Recording Size Calculator — Disk Space per Hour
A screen recording size calculator estimates the disk space a recording session will consume at a given quality preset — the check that prevents a long recording from dying in the last ten minutes.
Quick answer: At 1080p60 and 8 Mbps, one hour of screen recording is about 3.6 GB; at 4K60 and 45 Mbps it is about 20 GB. A two-hour tutorial session at 1080p60 therefore needs roughly 7–8 GB of free space before you start.
Formats: 90m · 1h30m · 5400s · plain number = seconds
Typical OBS / ScreenFlow output at balanced settings
Overrides the preset when filled — use the target bitrate from your encoder settings
| Duration | Size (decimal GB/MB) |
|---|---|
| 1 min | 60 MB |
| 5 min | 300 MB |
| 30 min | 1.8 GB |
| 1 h | 3.6 GB |
| 2 h | 7.2 GB |
| 10 h | 36 GB |
| 720p30 (light, 2.5 Mbps) | ~1.1 GB per hour |
|---|---|
| 1080p30 (standard, 5 Mbps) | ~2.3 GB per hour |
| 1080p60 (smooth, 8 Mbps) | ~3.6 GB per hour |
| 1440p60 (high, 16 Mbps) | ~7.2 GB per hour |
| 4K60 (max, 45 Mbps) | ~20 GB per hour |
| Rule of thumb | 0.45 GB per hour for every 1 Mbps of bitrate |
Screen content compresses unusually well
Static UI, text and slide content compress far better than camera footage: a coding session at 1080p30 can look perfect at 2.5 Mbps while a game capture at the same settings turns to mush during motion. That is why “record screen only” presets sit at half the bitrate of camera presets, and why gaming channels pay for more bits than tutorial channels.
Plan the disk before the session
Recording is unforgiving about free space: OBS stops when the target drive fills, and many users lose the interesting part of a session. Two habits prevent it — check the drive's free space against the per-hour figure first, and lower the preset when the disk is tight. A 32 GB USB stick holds about 8 hours at 1080p30 (light) or 1.5 hours at 4K60.
Format choices and editing
Recording directly to MP4 risks a corrupt file if the process crashes; MKV is safer and can be remuxed to MP4 afterwards without re-encoding. For editing, recording at a slightly higher bitrate than the final upload target gives the editor room to cut and zoom without visible degradation, and the archive copy can be re-encoded once the project is finished.
When to use this calculator
- Checking free disk space before a long tutorial or gameplay recording.
- Choosing a quality preset that fits a fixed-size SSD.
- Estimating how many sessions fit on an external drive.
- Planning storage for a course or webinar series.
- Deciding between 1080p and 4K recording for a given output target.