Video Recording Storage Calculator – Bitrate & Record Time

Choose the right recording mode

The Video Recording Storage Calculator now includes camera-video and screen-recording workflows on this page. Use the main form above for camera profiles, a known bitrate, clip counts and card capacity. Use the screen form below for screen activity assumptions or a measured test recording. The two forms keep their own inputs and results.

Calculate file size from bitrate

Stored bytes = (video bits per second + saved audio bits per second) × duration seconds ÷ 8 × (1 + overhead percentage ÷ 100). Multiply this result by the number of identical clips or recordings. Both modes use this relationship when you enter a known video bitrate.

In the Video Recording Storage Calculator, a known bitrate already describes the chosen recording configuration. Do not multiply it again by resolution, frame rate, activity or codec factors. Use settings-based estimates only when you do not have an actual average recording bitrate.

These are decimal gigabytes before display rounding. One Mbps means 1,000,000 bits per second; one MB/s means 1,000,000 bytes per second, equivalent to 8 Mbps. GB uses 1,000,000,000 bytes, while GiB uses 1,073,741,824 bytes. Changing the display unit changes the number shown, not the underlying data.

Use camera profiles and capacity checks

The Video Recording Storage Calculator retains resolution and frame-rate inputs, compressed recording profiles and the uncompressed reference. Profile names alone do not determine an exact rate: use the specific camera or recorder's published setting, or measure a representative file. Settings-based planning factors are assumptions rather than manufacturer specifications.

For multiple clips, enter the duration of one clip and its count. If their rates or lengths differ, calculate each group separately and add their storage. Audio bitrate means the total saved audio rate; do not add separate tracks again if your entered figure already includes them. For an audio-only project, use the Audio File Size Calculator.

The Video Recording Storage Calculator subtracts your reserved-space percentage from entered card or drive capacity. Maximum recording time divides that usable capacity by the modeled storage rate. Complete-clip count rounds down; a fraction of another clip is not a complete recording. A 128 GB card with 5% reserved provides 121.6 GB in this scenario. Actual formatted free space may differ.

Storage space and write performance are separate checks

Use the existing write-floor helper above to compare the modeled data rate, a chosen headroom allowance and the card's entered sustained-write floor. Enough capacity does not establish that recording will be reliable. The SD Association speed-class guidance explains minimum sequential performance under defined standard conditions. Check the camera's required card type and recording-mode instructions as well.

Plan screen capture from your own recording

Use the screen mode below for documents, scrolling, application use, video playback or gameplay. Its activity, quality, codec, pixel-count and frame-rate factors provide a planning estimate when no measured bitrate is available. These factors are not a universal encoder model.

For stronger project-specific evidence, record a representative sample with the same software settings, audio tracks and activity. The preserved test-recording helper projects its saved size to your target duration and recording count. A static desktop sample may underrepresent a session with rapid movement. Avoid stretching a short, unrepresentative clip into a precise long-session forecast.

The Video Recording Storage Calculator does not assume that selecting H.265 or AV1 automatically creates a particular saving. At the same entered bitrate and duration, the storage arithmetic is the same. Constant-quality recording can vary its bitrate with content; a nominal CBR or average VBR setting has different behavior. OBS recording guidance documents encoder-specific quality controls.

Check the estimate's limits

The Video Recording Storage Calculator does not inspect files, physical free space, encoder support or actual recording quality. Results exclude editing proxies, project caches and exports unless you include those separately. Long recordings may be split into files; segmentation and per-file structures can change overhead.

Display precision rounds the answer only. Use the underlying estimate with a suitable free-space allowance rather than treating the final decimal as guaranteed capacity. All forms retain their input validation limits. A missing required input is not a measured zero. Recalculate after changing settings, and compare the result with a real sample before committing to a long recording.

For multiple security cameras and retention schedules, use the CCTV Storage Calculator. Its camera-count and retention workflow remains separate from this single-recording planning page.