You enter the video duration in seconds, then select a resolution, frame rate, and codec. The tool looks up a typical bitrate for that resolution-codec combination, scales it linearly for frame rate relative to 30 fps, and multiplies by duration to estimate file size in megabytes or gigabytes. It assumes constant bitrate (CBR) encoding. Variable bitrate (VBR) files may be smaller for simple scenes or larger for complex ones.
Most cameras and encoders use variable bitrate (VBR), which adjusts quality on the fly. Scenes with lots of motion or detail use more data, while static shots use less. This calculator assumes constant bitrate, so treat the result as a reasonable midpoint.
H.264 is the most widely compatible and plays on virtually everything. H.265 cuts file size by roughly 30–50% but needs a newer device to decode smoothly. AV1 offers similar savings and is royalty-free, but hardware support is still rolling out.
Not exactly four times, but roughly 3–4× depending on the codec. 4K has four times the pixels, but modern codecs are more efficient at higher resolutions. Expect about 3× for H.265 and closer to 4× for H.264.
Switch to a more efficient codec (H.265 or AV1), lower the frame rate if smooth motion isn't critical, or use a tool like HandBrake to re-encode with a lower constant rate factor (CRF). Dropping from 60 fps to 30 fps alone halves the file size.
Estimate only. Results reflect your inputs and standard formulas. Double-check important decisions independently.