Media Production ToolsVideo File Size Calculator
Estimate an export size from duration and bitrate.
Estimated file size
- Exact bytes
- 759,600,000 bytes
- Size per minute
- 75.96 MB
- Size per hour
- 4.56 GB
- Total bitrate used
- 10.128 Mbps
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How this is calculated
The total bitrate is the video bitrate plus the audio bitrate when an audio track is included. Multiplying that by the duration gives a count of bits; dividing by eight gives bytes. Container overhead is then added as a percentage of the payload.
totalBitrateBps = videoBitrateBps + (includeAudio ? audioBitrateBps : 0) payloadBits = totalBitrateBps × durationSeconds payloadBytes = payloadBits / 8 fileSizeBytes = payloadBytes × (1 + overheadFraction)
Units
Bitrate is held in bits per second, capacity in bytes and duration in seconds, and values are converted only when you type them and when they are displayed. One byte is eight bits everywhere. Storage is decimal by default, so 1 GB is 1,000,000,000 bytes; the binary units are opt-in and are always named GiB rather than GB.
Assumptions
- The bitrate you enter is the average bitrate the encode achieves.
- Container overhead is 0% unless you set it, because the real figure depends on your container and muxer and no measurement is published here.
- No codec behaviour is modelled, and no bitrate is recommended for any platform.
Worked example
A 60-second clip at 10 Mbps video with a 128 Kbps audio track, with no container overhead:
totalBitrateBps = 10,000,000 + 128,000 = 10,128,000 bps payloadBits = 10,128,000 × 60 = 607,680,000 bits payloadBytes = 607,680,000 ÷ 8 = 75,960,000 bytes fileSizeBytes = 75,960,000 × (1 + 0) = 75,960,000 bytes display (MB) = 75,960,000 ÷ 1,000,000 = 75.96 MB
Every step is exact, so the answer is exactly 75.96 MB. This is test vector V1 in the calculator requirements, and the same arithmetic runs behind the calculator above.
Frequently asked questions
Why is my exported file a different size?
The calculation assumes the bitrate you enter is the average the encoder actually achieves. A variable-bitrate encode spends fewer bits on simple footage and more on complex footage, so the finished file can land either side of the estimate. Container structure, chapter and timecode metadata, and embedded thumbnails add a little more.
Does this use 1,000 or 1,024 bytes to a kilobyte?
Decimal by default: 1 MB is 1,000,000 bytes, which is how storage capacity and bitrate are advertised. Switch Unit system to Binary under Advanced to read the same size in KiB, MiB, GiB and TiB, where 1 MiB is 1,048,576 bytes. The underlying byte count never changes, only how it is expressed.
What should I enter for container overhead?
Leave it at 0 unless you have measured it. Overhead depends on the container, the muxer and the settings you use, so any number published here would be a guess. Set it to 0 to see the raw payload size, or enter the percentage you measured on a comparable export.
Should I include the audio track?
Include it whenever the export carries audio. Audio is a constant addition to the total bitrate, so at 128 Kbps it adds about 960 KB for every minute of runtime. Turn the toggle off for a silent export, or set the audio bitrate to 0, which has the same effect.
Can I share this result with someone?
Yes. Copy link writes the current inputs into the address as query parameters, so anyone opening that link sees the same values and the same result. Numbers travel in bits per second, bytes and seconds, so the link does not depend on which display units you happened to be using.