How to use the Video Bitrate Calculator
- Choose the resolution and frame rate you are encoding at; the recommended bitrate is filled in automatically.
- Adjust the video bitrate if you are targeting a specific quality or size.
- Enter the runtime in minutes and the audio bitrate in kilobits per second.
- Read the resulting file size, per-minute size and estimated upload time.
- Check the bits-per-pixel figure — below about 0.08 for H.264 usually means visible artefacts in motion.
How the calculation works
File size is bitrate multiplied by duration, with the audio track added. Because bitrate is quoted in bits per second and file sizes in bytes, the product is divided by eight. The relationship is exactly linear, so halving the bitrate halves the file size — quality, however, does not degrade linearly, which is the whole art of encoding.
Recommended bitrates scale with pixels per second, not resolution alone. 4K at 60 fps carries four times the pixels of 1080p60 and needs roughly four to seven times the bitrate for equal quality. The recommendations shown follow YouTube's published H.264 upload guidance, which is the most widely used reference point. Newer codecs shift the whole table: HEVC and AV1 reach comparable quality at roughly 30–50% lower bitrate, at the cost of far heavier encoding.
Bits per pixel per frame is the codec-independent quality signal. Divide bitrate by pixels multiplied by frame rate: values around 0.1 or above are comfortable for H.264, while heavy motion — sports, fast pans, confetti — needs more than static talking-head footage at the same setting. Constant-rate-factor encoding, which most people should prefer over fixed bitrate, varies the bitrate to hold quality steady and makes the resulting size only an estimate.
bytes = (video kbps + audio kbps) × 1000 × seconds ÷ 8; bits per pixel = bitrate ÷ (width × height × fps)Source: YouTube recommended upload encoding settings (H.264 bitrate table); ITU-T H.264 Advanced Video Coding specification.
Worked example
A 60-minute 1080p60 video at 8 Mbps video and 160 kbps audio.
- Total bitrate = 8,000 + 160 = 8,160 kbps.
- Seconds = 3,600, so bits = 8,160,000 × 3,600 = 2.94 × 10¹⁰.
- Bytes = 2.94 × 10¹⁰ ÷ 8 = 3.67 × 10⁹.
About 3.67 GB, roughly 61 MB per minute, and about 24 minutes to upload on a 20 Mbps line.
Frequently asked questions
Should I use constant bitrate or CRF?+
CRF for anything you are storing or uploading — it spends bits where they are needed. Fixed bitrate is for live streaming, where the link has a hard ceiling.
Why does my file come out smaller than predicted?+
Variable-bitrate encoding undershoots the target on easy footage. The prediction assumes the bitrate is sustained throughout.
Does higher bitrate always mean better quality?+
Only up to the point where the encoder stops discarding information. Beyond that you are storing bits with no visible benefit.
How much can AV1 save?+
Typically 30–50% at equal quality against H.264, but encoding is much slower and older devices may not decode it in hardware.
Last reviewed September 1, 2026. We review this page whenever the underlying formula, tax year, published rate or standard changes.