Home › Video Bitrate Calculator
Video uses decimal gigabytes: 1 GB = 1000 MB.
Video Bitrate Calculator
Upload limits, email attachments, and streaming platforms all care about file size, not bitrate. Tell this calculator your target size and video length, and it works backwards to the exact video bitrate you need, in Mbps and Kbps.
-Required video bitrate
-Bitrate in Kbps
The bitrate formula
Video bitrate (Mbps) = file size (MB) x 8 / duration (seconds). Multiplying by 8 converts megabytes to megabits, because bitrate is measured in bits per second while file sizes are measured in bytes. If you enter gigabytes, the calculator converts with 1 GB = 1000 MB, the decimal convention used across video platforms and encoders.
Worked example
Target: 250 MB. Duration: 10 minutes = 600 seconds.
- 250 x 8 / 600 = 3.33 Mbps.
- 3.33 x 1000 = 3,333 Kbps.
- Reserve 0.16 Mbps for audio, so the total stream is about 3.49 Mbps.
Why you must reserve bitrate for audio
An encoder splits the total bitrate between video and audio. If you set the total to the calculated 3.33 Mbps, the video track gets less once audio takes its share, and the file still lands near the target. The safe move is to set the video bitrate to the calculator's number and add roughly 128 to 160 Kbps of audio on top.
Bitrate is not the same as quality
The same bitrate looks very different depending on the codec. H.265 (HEVC) and AV1 deliver roughly the same visual quality as H.264 at 30 to 50 percent less bitrate. Resolution and frame rate also raise the requirement: 4K at 60 fps needs far more bits than 1080p at 30 fps to look equally clean, so use this number as a starting point and adjust to taste.
Planning estimate only. Results use the list prices shown and may differ from your actual bill. Terms
Frequently asked questions
What bitrate do I need for YouTube 1080p?
YouTube suggests 8 Mbps for standard 1080p uploads and 12 Mbps for high frame rate 1080p. Use this calculator when you have a hard file size limit instead, for example an email attachment or a platform upload cap.
Does 1 GB mean 1000 or 1024 MB here?
This calculator uses 1 GB = 1000 MB, the decimal convention used by video platforms, encoders, and storage marketing. Operating systems sometimes show 1 GiB = 1024 MiB, which is a different unit.
Should I use constant or variable bitrate?
Variable bitrate (VBR) usually gives better quality per megabyte because it spends bits on complex scenes and saves them on simple ones. Use the calculated number as the average or target bitrate in a two-pass VBR encode.
Why did my exported file come out bigger than the target?
Most likely the audio track was not accounted for, or the container adds overhead. Add the 0.16 Mbps audio reserve from the note above, and keep a small margin under strict limits.