Video File Size Cheat Sheet: How Big Is an Hour of Footage?
“How much storage do I need?” is the least glamorous question in video production and the one with the most expensive wrong answers. Bookmark this table — or learn the 10-second formula below it and never need the table again.
One hour of footage, by format
| Format | Bitrate | 1 hour ≈ |
|---|---|---|
| Phone video, 1080p30 (HEVC) | ~8 Mbps | 3.6 GB |
| Phone video, 4K30 (HEVC) | ~50 Mbps | 22 GB |
| GoPro 4K60 | ~78 Mbps | 35 GB |
| Streaming quality (Netflix-class 4K) | ~16 Mbps | 7 GB |
| YouTube upload master, 4K30 | 40 Mbps | 18 GB |
| Broadcast XDCAM HD 1080i | 50 Mbps | 22.5 GB |
| Mirrorless camera 4K (H.264 All-I) | ~400 Mbps | 180 GB |
| ProRes 422, 1080p25 | ~122 Mbps | 55 GB |
| ProRes 422 HQ, UHD 25p | ~734 Mbps | 330 GB |
| ProRes 4444, UHD 25p | ~1,100 Mbps | 495 GB |
| ARRIRAW / camera raw, 4K | 2,000+ Mbps | 1 TB+ |
(All figures approximate; VBR codecs vary with content complexity.)
The formula that replaces the table
File size = bitrate × duration ÷ 8.
Bitrate is in bits per second; dividing by 8 converts to bytes. Handy mental shortcuts:
- 1 Mbps ≈ 450 MB per hour — the only conversion factor worth memorizing
- So 8 Mbps ≈ 3.6 GB/hr, 50 Mbps ≈ 22 GB/hr, 100 Mbps ≈ 45 GB/hr
- Audio is rounding error in video projects (320 kbps ≈ 140 MB/hr)
Or skip the arithmetic: our bitrate & file size calculator does it both directions — size from bitrate, or the bitrate you need to hit a target size.
Storage planning for a shoot
Producers’ rule: estimated camera hours × format size × 3. The ×3 covers dual-recording/backup copies plus the working copy on the edit machine. A two-day interview shoot on a mirrorless at 400 Mbps (≈180 GB/hr) with 6 recorded hours needs roughly 1.1 TB × 3 ≈ 3.3 TB of healthy storage. Suddenly those “huge” 2 TB drives look small — this is why professional shoots budget storage as a line item.
Editors add proxies (small — a whole feature in 720p proxy fits in tens of GB), renders and exports. A safe planning figure for a serious project is camera media × 4 by the time it’s delivered and archived.
Why your export doesn’t match the estimate
Three usual suspects:
- VBR overshoot — variable bitrate encoders exceed the average on complex scenes. Budget +5–10%.
- The audio you forgot — 8 tracks of uncompressed WAV in a broadcast master adds real gigabytes.
- Wrong units — storage vendors sell decimal gigabytes (10⁹ bytes); your OS may report binary GiB (2³⁰). A “500 GB” drive shows ~465 GiB before a single file lands on it. Nobody is stealing your space; it’s marketing arithmetic.