bitrate calculator

the bitrate formula

the bitrate that fills a file of a given size

bitrate questions

the answers people look for most

how do you calculate bitrate from file size?

video bitrate = file size × 8 ÷ length, minus the audio bitrate. for a 100 MB file that's 5 minutes long with 128 kbps audio: 100 × 8,000 ÷ 300 − 128 = 2.54 Mbps.

what bitrate should i use for 1080p?

youtube recommends 8 Mbps for 1080p at 24–30 fps and 12 Mbps at 48–60 fps, for standard (SDR) video. that's for uploads, which youtube re-encodes, so it's on the generous side.

what bitrate should i use for 4K?

youtube recommends 35–45 Mbps for 4K at 24–30 fps and 53–68 Mbps at 48–60 fps, for SDR uploads.

why is my file bigger than the size i aimed for?

encoders don't hit a bitrate exactly — busy scenes use more — and the container adds a little on top. encode about 5% under the calculated bitrate, which the calculator shows, or use two-pass encoding, which is much better at landing on a size.

what's the difference between Mbps and MB/s?

Mbps is megabits per second, used for bitrates. MB/s is megabytes per second, used for file sizes and transfer speeds. there are 8 bits in a byte, so 8 Mbps is 1 MB/s.

what audio bitrate should i use?

youtube recommends 128 kbps for mono, 384 kbps for stereo and 512 kbps for 5.1 surround. screen recordings without sound need none, which leaves the whole budget for video.