How this calculator works
A raw video frame is a bitmap, so its size is the pixel count times the bits per pixel divided by eight. Ten-bit video stores ten bits for every colour sample, and because the three colour components are usually carried together the figure here is the total bits per pixel. Multiplying the frame size by the frame rate gives the uncompressed bitrate, and multiplying by the clip length gives the clip size. Real codecs such as H.264, ProRes and DNxHR compress each frame or a group of frames, so the recorded file is much smaller than this raw size. Uncompressed figures are still used to size capture buffers, network links and storage for editing workstations.
Formula
frame size (bytes) = width x height x bits per pixel / 8. bitrate (bit/s) = frame size x 8 x frame rate. clip size = frame size x frame rate x clip length. clip length = storage / (frame size x frame rate).
Worked example
A 1920 by 1080 frame at 10 bits per pixel needs 1920 x 1080 x 10 / 8 = 2,592,000 bytes, or 2.592 megabytes. At 24 frames per second the raw bitrate is 2,592,000 x 8 x 24 = 497,664,000 bit/s, about 497.7 Mbit/s. A ten second clip needs 622,080,000 bytes, about 622 megabytes. One gigabyte of storage lasts 1,000,000,000 / (2,592,000 x 24) = 16.08 seconds.
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Frequently asked questions
Why is my camera file far smaller?
Your camera compresses each frame, often heavily. H.264 and HEVC can reduce a frame to a small fraction of its raw size by describing motion and discarding detail the eye is unlikely to notice. The raw size is what the frame becomes in memory for editing.
Should I enter 10 or 30 bits for 10-bit colour?
Enter the total bits per pixel. A 10-bit RGB frame is often stored as 30 bits per pixel, while a 10-bit YUV 4:2:2 frame uses 20 bits per pixel. Manufacturer specifications quote whichever figure applies to their format.
Does the frame rate affect the frame size?
No, a single frame is the same size at any rate. Frame rate affects the bitrate and clip size, which is why doubling the frame rate doubles storage for the same duration.
What about audio and container overhead?
They add a small amount on top. Uncompressed audio is roughly 1.5 Mbit/s per stereo pair at CD quality, far less than uncompressed video, but it is not included in this figure.