How do you calculate a video file size?

Size equals bitrate times duration: size (bytes) = bitrate (bits/s) × seconds ÷ 8. This tool estimates the bitrate from the codec, resolution and fps using typical bits-per-pixel values for each codec.

What bitrate do I need for ProRes 422 HQ at 1080p?

ProRes 422 HQ is around 220 Mbps at 1920×1080 and 29.97 fps. The figure scales with resolution and frame rate; enter your values to see it.

Video bitrate & file size calculator

Parameters

Codec / quality

Resolution

Frame rate (fps)

Duration

About this calculator

A video file size is bitrate × duration. For intra-frame professional codecs (ProRes, DNxHR) the bitrate is essentially constant and scales with resolution and fps; for delivery codecs (H.264, H.265) the figure is indicative because they depend on content and encoder settings.

Where do the bitrates come from?

They are estimated with a bits-per-pixel (bpp) model: bitrate = bpp × width × height × fps. The bpp values are calibrated against published data rates for each codec (e.g. ProRes 422 HQ ≈ 220 Mbps at 1080p29.97).

Is it accurate for H.264 / H.265?

It is a high-quality delivery reference. Real bitrate depends on the encoder, preset, content (motion, grain) and CBR vs VBR. Use it for planning, not as an exact figure.