What this Video File Size Calculator does
The Video File Size Calculator estimates how much storage a video will use from three settings: its duration, video bitrate, and audio bitrate. It reports an estimated file size in decimal megabytes (MB). This is useful during content and media production when planning camera settings, exports, project storage, or delivery requirements.
The calculation is based on the amount of data sent each second. It combines the video bitrate with the audio bitrate, multiplies that total by the duration in seconds, and converts bits to bytes and then bytes to decimal megabytes. With the default values of 10 minutes, 8 Mbps video, and 192 kbps audio, the estimate is 618 MB.
This is a bitrate-based estimate rather than a measurement of a finished file. It assumes the listed bitrates remain constant for the whole duration. Actual output can differ because of variable bitrate encoding, container overhead, subtitles, metadata, extra audio tracks, and export settings. The tool does not inspect or compress a media file.
How to use the Video File Size Calculator
Enter the duration and the average or target bitrates you expect to use. Bitrate values should come from the camera, encoder, or export preset where possible. Check the units carefully because video bitrate is entered in megabits per second (Mbps), while audio bitrate is entered in kilobits per second (kbps).
- Video duration: enter the total running time in minutes. For example, a 90-second clip is 1.5 minutes.
- Video bitrate: enter the video stream's bitrate in Mbps. If a setting is shown in Kbps, divide it by 1,000 before entering it here.
- Audio bitrate: enter the audio stream's bitrate in kbps. If there is no audio track, enter zero.
Use the result to estimate storage for a single export, then multiply it by the number of versions or copies you plan to retain. For a production with several deliverables, calculate each one separately if their duration or bitrate differs. Treat the output as a planning figure and leave practical room for other project files and export variation.
How the Video File Size Calculator formula works
The formula adds video and audio data rates after converting both to bits per second. Video bitrate in Mbps is multiplied by 1,000,000. Audio bitrate in kbps is multiplied by 1,000. Duration in minutes is multiplied by 60 to get seconds. The combined rate is multiplied by that duration, divided by 8 to convert bits to bytes, and divided by 1,000,000 to express the result in decimal MB.
Worked example: consider a 12-minute video with a video bitrate of 6 Mbps and audio bitrate of 160 kbps.
- Convert duration: 12 × 60 = 720 seconds.
- Convert and combine bitrate: (6 × 1,000,000) + (160 × 1,000) = 6,160,000 bits per second.
- Estimate bytes: 720 × 6,160,000 ÷ 8 = 554,400,000 bytes.
- Convert to decimal megabytes: 554,400,000 ÷ 1,000,000 = 554.40 MB.
The calculation applies one combined rate across the full runtime. If you know only a target bitrate, the estimate is only as representative as that target is of the encoded file.
Use cases for the Video File Size Calculator
Estimating file size can help production teams make decisions before recording or exporting. A rough estimate can reveal whether a planned deliverable is likely to fit within available storage or whether a bitrate target may need review. It can also help compare two export plans when the duration stays the same.
- Storage planning: estimate the size of a recording session's final exports and account for multiple cuts, languages, or formats.
- Production planning: compare expected sizes at different bitrate settings before committing to a delivery plan.
- Media handoff: give collaborators a reasonable estimate of the file volume involved in an upcoming transfer.
- Archive preparation: estimate how much space a set of finished videos may occupy, then add room for source footage and project files separately.
For a batch of similar videos, calculate one representative item and multiply the estimate by the number of items. If runtimes or bitrates vary significantly, estimate each group separately instead of treating the whole batch as uniform.
Other factors to consider when calculating video size
Encoded video often uses variable bitrate. In that case, the bitrate can rise for detailed motion or complex scenes and fall for simpler material. A target bitrate may describe an average, a cap, or an encoder goal depending on the software. Use the average bitrate when available for the closest estimate.
Audio also varies. A file may contain multiple language tracks, commentary, or surround audio, each of which adds data. Subtitles, chapters, metadata, and the container format contribute additional overhead. These additions are usually not represented in the simple bitrate formula, so the final file can be somewhat larger.
Storage units can cause confusion. This calculator uses decimal MB, where 1 MB is 1,000,000 bytes. Some operating systems display binary mebibytes (MiB), where 1 MiB is 1,048,576 bytes, and may label them as MB. A displayed number can therefore differ even when it describes the same byte count.
Keep source recordings and editing assets in a separate estimate from the final export. Camera originals, proxies, project files, cache data, and duplicate deliverables can require more room than the finished video alone. The calculator estimates one encoded video and audio stream based on the entered inputs.
Frequently asked questions
How accurate is this video size estimate?
It is a useful approximation when the entered bitrates reflect the video's average rates. Variable bitrate encoding, file overhead, additional tracks, and export settings can make the actual size higher or lower. For precision, compare the estimate with a test export made using the intended settings.
What is the difference between Mbps and MB?
Mbps means megabits per second, a data rate. MB means megabytes, a quantity of stored data. There are eight bits in a byte, so the formula divides total bits by eight before converting to megabytes.
Should I enter the maximum or average bitrate?
Use the average bitrate for a typical size estimate. A maximum bitrate is a ceiling and may not be sustained through the video, so using it can overstate the expected size. If only a target is available, understand that the result remains an estimate.
Does the estimate include subtitles or multiple audio tracks?
No. The inputs represent one video stream and one audio stream. Add the bitrate of additional audio streams to the audio total for a rough adjustment, while remembering that subtitles and container data are not included in the formula.
Can I estimate a video with no sound?
Yes. Set audio bitrate to zero. The result then reflects the entered video bitrate and duration, with the same limitations around variable encoding and file overhead.