Video File Size Calculator in the browser is not a generate
/free-tools/video-file-size-calculator never spends a credit. Do not pay a model to do an in-browser file job.
/free-tools/video-file-size-calculator never spends a credit. Do not pay a model to do an in-browser file job. How large a clip will be is bitrate times duration, plus the audio stream people forget. Arithmetic. Not a reason to generate a proxy "to see how big it comes out."
Versely bills generation in credits. There is no 0-credit model and no free trial for a render. File-size math is not a render. The calculator runs on numbers you type — no upload, no account — before you spend, which is the only honest time to use it.
File size is bitrate times time
The formula the tool prints is the one it uses: (video kbps + audio kbps) × seconds / 8, reported in mebibytes the way an OS reports them (base 1024). Bitrates are decimal kilobits. The estimate is what Finder and Explorer will roughly show.
Audio counts. A 128 kbps track on a 10-minute video is about 9 MB by itself. Punch only the video bitrate and you miss the cap by the soundtrack.
Defaults — 8,000 kbps video, 128 kbps audio, one minute, 100 MB target — are knobs, not a platform recommendation. Put in the encoder settings you actually use.
A generate cannot answer this. Models do not take "make it 80 MB." They take duration, resolution, audio on or off — choices that move the credit formula, not a megabyte budget.
Two directions from the same sum
Size from bitrate. Duration and rates in, estimated MB (or GB) out.
Bitrate from a cap. Duration and a hard upload limit in; video kbps you can afford after subtracting audio. Encoders average around a target. Leave headroom.
The second direction is email, LMS, marketplace slots. It is also the loop people fake with a generate: render, inspect Finder, delete, render again. Each pass is billed. The arithmetic was free. Treat the figure as accurate within a few percent — container overhead and VBR are real. It is not a promise from an encoder you have not run.
Why the export is never exact
Most encoders are VBR. Complex motion spends more; a locked still spends less. Average lands near the target.
If you already have the file, weigh the file. The calculator is for the clip you have not encoded yet. After the encode, the OS number wins.
Do not confuse credit cost with file size. A 4K row can be a large credit bill and still fit a 100 MB cap; a cheap 720p row can miss 25 MB if bitrate stays high. Cost is structurally different credit formulas. None of them are "megabytes of H.264."
Credits buy a render, not a spreadsheet
Free tools never call a model or send your media. Calculators are the extreme of that — there is not even a file. Generation is the opposite: hardware, a catalog row, a quote before you confirm.
Pick duration and a bitrate cap before you pick the row. Then generate at the length you meant to ship. Harvesting a 30-second take to learn it will not upload is donating a billed pass to a form field. If the cap is the product constraint, encode for it in an editor after you like the picture. Do not pay a model to be the calculator.
FAQ
Does the calculator upload my video?
No. It does not take a video. It takes numbers. There is nothing to upload, nothing to store, and nothing to delete.
Why is my export a different size than the estimate?
Variable bitrate plus container overhead. The page says so. Leave headroom against a hard limit, and weigh the real file once you have it.
Can I use this to pick a Versely model?
Indirectly. Models are billed in credits by duration, resolution, and sometimes audio — see cost — not by output megabytes. Use the calculator for the upload cap. Use the catalog quote for the bill. They are not the same axis.
Is it actually free?
Yes. It is arithmetic in the browser. Generation on Versely is never 0 credits. Do not run a model to answer a question this page already did.