💾 Video File Size Calculator
Enter the clip length and your video and audio bitrates to estimate the video, audio, and total size in MB and GB — plan storage, delivery, and upload times before you hit export.
🧮 Estimate Your File Size
What is a Video File Size Calculator?
It predicts how big a rendered clip will be before you export it. Video and audio are stored at a set number of bits per second — the bitrate — so multiplying that by the length and converting to bytes gives the file size. This tool separates the video and audio streams, adds them, and shows the total in megabytes and gigabytes.
Use it to check a clip will fit on a drive, to compare bitrate settings before a long render, or to estimate how long an upload will take. Real files vary a little with variable-bitrate encoding and container overhead, so treat the figure as a close, practical estimate.
❓ Frequently Asked Questions
How does the video file size calculator work?
Enter the clip length in seconds, the video bitrate in megabits per second, and the audio bitrate in kilobits per second. File size is bitrate multiplied by duration, divided by eight to convert bits to bytes — the tool does this for video and audio separately, adds them, and reports the total in both megabytes and gigabytes.
What is bitrate and how does it affect size?
Bitrate is how much data is used to store each second of video or audio. A higher bitrate means more detail and a larger file; a lower bitrate saves space but can introduce compression artifacts. Because size scales directly with bitrate, halving the bitrate roughly halves the file — the single biggest lever over how big your export ends up.
Why is my real file size a little different from the estimate?
This tool assumes a constant bitrate, but most encoders use variable bitrate, spending more data on complex, fast-moving shots and less on simple ones. Container overhead, metadata, and codec efficiency also nudge the number. The estimate is close and ideal for planning storage and upload times, but expect small differences in the final file.
What bitrate should I use for animation?
It depends on resolution and platform. As a rough guide, 1080p delivery often sits around 8–12 Mbps and 4K around 35–45 Mbps, with 256–320 kbps for audio. Flat, clean animation compresses well, so you can often go lower than live action, but always check the recommended settings for the platform you're uploading to.