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Quick answer
What does the Video file size calculate?
What file size follows from bitrate and video duration? This calculator uses video bitrate, audio bitrate, video duration, and container overhead to estimate encoded video size immediately in your browser.
With the values currently entered, the result is 4.28 GB — estimated video file size. It also shows total bitrate, and storage per hour.
How to use the Video file size
- Replace the example values with your own numbers.
- Review the result and supporting figures as they update automatically.
- Check the formula and assumptions before using the estimate for a decision.
Inputs used
- Video bitrate — entered in Mbps
- Audio bitrate — entered in Mbps
- Video duration — entered in minutes
- Container overhead — entered in %
Video file size formula
(Video + audio bitrate) × duration ÷ 8 × container overhead
Assumptions
- Average bitrate stays at the entered level.
- One gigabyte is treated as 1,000 megabytes for file size.
Practical guide
Video file size example and edge cases
What file size follows from bitrate and video duration? Let's use a concrete example, then look at the assumptions that can move the answer.
Example: A practical video file size scenario
For this example, use video bitrate of 12 Mbps, audio bitrate of 0.32 Mbps, video duration of 45 minutes, and container overhead of 3 %. These are starting values, so replace them with numbers that match your situation.
- Video bitrate
- 12 Mbps
- Audio bitrate
- 0.32 Mbps
- Video duration
- 45 minutes
- Container overhead
- 3 %
Calculated result4.28 GBestimated video file size
Start with estimated video file size. Then check total bitrate, and storage per hour to understand what sits behind the main result.
Example results use the default display profile. The calculator above follows your selected country and units.
How to read the result
- Read the main result first. The supporting figures for total bitrate, and storage per hour explain how the estimate is built.
- The method is (Video + audio bitrate) × duration ÷ 8 × container overhead. Keep the units consistent and use values from the same time period.
Edge cases worth checking
When video bitrate is unusual
Average bitrate stays at the entered level. Double-check this input before relying on the result.
When container overhead is uncertain
One gigabyte is treated as 1,000 megabytes for file size. Run a lower and higher value to see a useful range.
What changes the result most
Video bitrate
Test a lower and higher video bitrate. A small percentage change can move the final result more than expected.
Audio bitrate
Test a lower and higher audio bitrate. A small percentage change can move the final result more than expected.
Video duration
Keep video duration on the same time basis as the other inputs. Monthly and annual values are easy to mix up.
Try a different scenario
Small changes show whether the answer is stable or sensitive.
Video bitrate: 10% lower
11 Mbps3.94 GBestimated video file size
Video bitrate: 10% higher
13 Mbps4.63 GBestimated video file size
Audio bitrate: 10% higher
0.352 Mbps4.29 GBestimated video file size
Common mistakes
Check video bitrate
Average bitrate stays at the entered level. Make sure this matches the number you enter.
Keep container overhead consistent
One gigabyte is treated as 1,000 megabytes for file size. Use the same units and time period throughout the calculation.
Do not rely on one video file size scenario
Run a cautious case and an optimistic case. The range is often more useful than one exact-looking number.
Use this result well
What file size follows from bitrate and video duration?
Real speed, compression, battery health, and device overhead can change the result.