What this calculator does
The Streaming Bitrate Calculator converts a media stream's bitrate (in megabits per second, Mbps) and its duration (in seconds) into an estimated file size and the bandwidth needed to stream it without buffering. It works for video, audio, screen recordings, podcasts and live broadcasts.
How to use it
Enter the stream bitrate in Mbps and the duration in seconds. The tool returns the total file size in megabytes (MB) and gigabytes (GB), plus the minimum sustained download speed (in Mbps) required to play it in real time.
The formula explained
Bitrate measures bits per second, but storage is measured in bytes — and there are 8 bits in a byte. So multiplying bitrate (Mbps) by duration (seconds) gives total megabits, and dividing by 8 converts to megabytes:
$$\text{File Size (MB)} = \frac{\text{Bitrate (Mbps)} \times \text{Duration (s)}}{8}$$
Because every second of playback must arrive on time, the required bandwidth simply equals the stream's bitrate.
Worked example
A 1080p video encoded at 5 Mbps running for 3600 seconds (one hour): $$5 \times 3600 \div 8 = 2250 \text{ MB}$$ or about 2.2 GB. To stream it live you need a connection of at least 5 Mbps.
FAQ
Why divide by 8? Internet speeds are quoted in bits, file sizes in bytes; 8 bits = 1 byte.
Is this exact? It is a clean theoretical estimate. Real files vary slightly with container overhead and variable bitrate (VBR) encoding.
What about Kbps? Divide Kbps by 1000 to get Mbps before entering it (e.g. 320 Kbps = 0.32 Mbps).
