Recording Storage Calculator
Work out how much disk space a recording session will use at your settings — and see how many of those recordings fit on common SD cards, SSDs and drives before you press record.
How it works
The tool converts your video bitrate + duration into a file size using the standard formula: size in megabytes = (bitrate in Mbps × duration in seconds) / 8. It uses decimal units (1 GB = 1000 MB), which matches how storage devices are labelled on the box. Default bitrates are H.264 sweet spots for each resolution and frame rate — bump them up for high-motion / studio recording, or leave them as-is for talking-head video.
How to use this tool
- Pick the resolution you'll record at.
- Pick the frame rate — 24 for cinematic, 30 for standard, 60 for gameplay/sports.
- The bitrate auto-fills to a sensible default. If your camera or encoder uses something specific (e.g. Sony XAVC-S at 100 Mbps), type that in.
- Enter how long you'll be recording.
- The right-hand panel updates as you type — file size on top, and a table showing how many of these recordings fit on common storage.
Frequently asked questions
Where do the default bitrates come from?
They're widely-accepted H.264 targets for each resolution: 720p ≈ 5–8 Mbps, 1080p ≈ 8–15 Mbps, 1440p ≈ 16–30 Mbps, 4K ≈ 40–80 Mbps. Camera manufacturers and streaming platforms publish similar ranges. If you shoot in ProRes, XAVC-S, or All-I, your actual bitrate will be several times higher — override the field with your real number.
Why is my camera's file bigger than the estimate?
Two reasons: (1) your camera may record at a higher bitrate than the H.264 default here — Sony and Panasonic often shoot at 100 Mbps for 4K, not 80. (2) If you record All-Intra (every frame is a keyframe), the file can be 3–5× larger than the equivalent Long-GOP file. Type in the exact bitrate from your camera's spec sheet for an accurate estimate.
GB vs GiB — which one does this use?
Decimal GB (1 GB = 1,000,000,000 bytes), which is how storage devices are labelled. A "128 GB" SD card holds 128 decimal GB. If you compare against your operating system's file browser it might show slightly smaller numbers (Windows and older macOS use GiB / binary) — that's why the "how many fit" figures err on the conservative side.
Does this account for audio?
Not directly. Audio is 128–320 kbps depending on your camera — small compared to video (about 1–3% of the total). If you're doing a music-focused recording at 320 kbps stereo, add roughly 2.5 MB per minute of audio to the estimate.
What's a safe buffer to leave on the card?
Never fill an SD card past ~90%. Modern cards need free space for wear-levelling; a full card can drop frames or refuse to finalise the file. Also, at the top end, most cards fragment file writes and slow down — 80% is a comfortable ceiling for long recordings.