Video Storage Calculator

Video file size: bitrate times duration

File size equals size = bitrate · duration. Just watch the bit-vs-byte units. Example: one hour of video at 8 Mbps gives you 8·10⁶ · 3600 = 28.8 Gb = 3.6 GB. RAW (uncompressed) footage is enormous. 1080p 30 fps 8-bit RGB pumps out roughly 187 MB/s, which works out to ~670 GB/h. Inter-frame compression (the P-frames and B-frames) cuts that down by anywhere from 10 to 100×. ProRes intermediate sits near 22 MB/s for 1080p, which is handy while you edit. Editing codecs like DNxHR and ProRes do a different job than delivery codecs like H.264 and H.265. Editing wants fast decode and high quality per frame; delivery wants small files at a quality you can live with. And don't forget the audio bitrate (128–320 kbps) and container overhead (~1–2%), because those add up too.

Applications: editing storage, surveillance and archiving

Editors use it to size SSDs and HDDs for project bins, since ProRes 4K eats around 1 TB per 10 hours. CCTV planners estimate disk for round-the-clock recording, where a 2 Mbps camera piles up ~22 GB/day, or 660 GB/month. Studios run the numbers for archiving finished projects on LTO tape or cloud cold storage. And IT admins use it to set Zoom or Google Meet recording bitrate so they don't burn through local disk and bandwidth.

FAQ

Does resolution dictate file size? Only indirectly. Bitrate is what actually drives it. A heavily compressed 4K clip can come out smaller than uncompressed 720p. What resolution does is set a sensible bitrate target.

Why is my exported file larger than the bitrate suggests? Audio, subtitles, extra tracks and container overhead all pile on. Two-pass VBR can also run past the average target during complex scenes.

How much storage for a 1-hour 4K recording? At H.265 35 Mbps you get 35·10⁶ · 3600 / 8 ≈ 15.75 GB. The same hour in RAW would push past 670 GB.