Video File Size Calculator

File size in megabytes equals the bitrate in megabits per second times the duration in seconds, divided by 8. There are 8 bits in a byte, so a 10 Mbps clip stores 1.25 megabytes for every second it runs.

Bitrate is quoted in bits per second while file size is measured in bytes, and one byte is 8 bits. Dividing megabits by 8 converts the streaming rate into a storage figure, which is why the /8 step appears in every direction of the calculation.

Decimal units, so 1 GB is 1000 MB and 1 MB is 1000 KB. That matches how drive capacity and most streaming and upload guidelines are quoted. If a program reports binary GiB, its number will read slightly smaller.

Yes. The Solve for menu switches which of the three values is the unknown. Fill in the other two and the tool rearranges the same formula, so you can find the bitrate that hits a size cap or the runtime that fits a storage budget.

It uses whatever bitrate you type. For a full-file estimate, enter the total (video plus audio) bitrate. If you only know the video bitrate, add the audio bitrate to it first, since a stereo AAC track of 128 to 256 kbps adds up over a long clip.

Variable bitrate encoding, container and metadata overhead, and changing scene complexity all shift the true size. This calculator assumes a steady average bitrate, which is a close estimate for most exports but rarely exact to the byte.

Bitrate in Mbps, duration in seconds, and file size in MB. If your bitrate is in kbps, divide by 1000 first (8000 kbps is 8 Mbps). For minutes, multiply by 60 before entering the duration.

Each field the tool needs must be a number greater than zero. If a required value is empty, zero or negative, it shows a short prompt instead of a result so you never get a divide-by-zero or a nonsense size.

No. It is a plain arithmetic calculation that runs in your browser. Your numbers never leave your device, and the tool keeps working offline once the page has loaded.