Video File Size CalculatorFree online other calculator — instant results, no sign-up
Estimate video size from total bitrate and duration, excluding overhead.
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About the Video File Size Calculator
The Video File Size Calculator estimates video file size from total bitrate in Mbps and duration in minutes, excluding file overhead. Use it to estimate storage needs when you know the combined bitrate of the streams you plan to save. With the default inputs of 10 Mbps and 60 minutes, the estimated size is 4.5 GB.
- Total bitrate (Mbps)
- The combined average bitrate of the video, audio, and any other included streams, expressed in megabits per second (Mbps), with a default of 10.
- Duration (min)
- The video's total running time in minutes, with a default of 60.
Formula and method
S = (B × 10^6 × T × 60) / (8 × 10^9) = 0.0075 × B × T; with the defaults, S = 0.0075 × 10 × 60 = 4.5 GB.
- SEstimated size in decimal gigabytes (GB), where 1 GB equals 1,000,000,000 bytes.
- BTotal bitrate in megabits per second (Mbps), where 1 Mbps equals 1,000,000 bits per second.
- TDuration in minutes.
Convert the bitrate from megabits per second to bits per second and the duration from minutes to seconds. Multiply them to obtain the total number of bits, divide by 8 to convert bits to bytes, and divide by 1,000,000,000 to express the result in decimal GB. For 10 Mbps over 60 minutes, this gives 36,000,000,000 bits, or 4,500,000,000 bytes, equal to 4.5 GB.
Worked example
These are the calculator's starting values and the results it actually produces for them.
Inputs
- Total bitrate10 Mbps
- Duration60 min
Results
- Result4.5 GB
How to use the Video File Size Calculator
- 1Find the total average bitrate of the video and audio streams; add their bitrates if they are listed separately.
- 2Enter that total in Total bitrate (Mbps), converting any values reported in other units to Mbps first.
- 3Enter the full running time in Duration (min).
- 4Read the estimated size in GB; the default values of 10 Mbps and 60 minutes produce 4.5 GB.
- 5Allow additional storage for container overhead and any uncertainty in the average bitrate.
Reading your result
The Result row shows the estimated stream data size in decimal GB, excluding overhead. A result of 4.5 GB means approximately 4.5 billion bytes of encoded data for the entered total bitrate and duration, not a guaranteed final file size.
Limitations
The estimate assumes the entered bitrate is constant or accurately represents the average across the entire video. It excludes container overhead, metadata, indexes, and any stream data not included in the total bitrate. Variable-bitrate encoding may produce a different size if you enter a target or peak bitrate instead of the actual average. Resolution, frame rate, and codec are not separate inputs: their effect on size is reflected in the bitrate. Some systems report binary GiB rather than decimal GB, so the displayed numerical size may differ even for the same byte count.
Common questions
Should Total bitrate (Mbps) include audio?+
Yes. Include the combined average bitrate of video, every audio track, and any other streams you want counted. Entering only the video bitrate will omit the storage used by audio.
Can I use this calculator for variable-bitrate video?+
Yes, if you use the average total bitrate over the full duration. A target bitrate gives an approximate estimate, while a peak bitrate is not representative of typical file size.
Why does 10 Mbps for 60 minutes produce 4.5 GB?+
The duration is 3,600 seconds, so the encoded data totals 36,000 megabits. Dividing by 8 gives 4,500 megabytes, which equals 4.5 decimal GB.
Do I need to choose a codec or resolution?+
No. Once total average bitrate and duration are known, they determine the estimated data size regardless of codec or resolution. Those settings affect visual quality and the bitrate needed, rather than changing this calculation.
Does the calculator save my information?+
Calculations run in your browser. While signed in, inputs and results are automatically recorded in account history; saving a result creates a separate saved record.
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Results are estimates for informational purposes and are not financial, medical or legal advice.