/ Creator

The Bitrate Accountant

Know before you shoot.

A video bitrate calculator estimates file size by multiplying the bitrate by the recording time, then converting bits to bytes: file size = bitrate (Mbps) x seconds / 8 / 1024 gigabytes. A 100 Mbps clip recorded for 10 minutes lands at about 7.32 GB. Each audio track adds roughly 2.3 Mbps before the math runs.

How it's calculated

Three steps, all from the bitrate and the clock:

  • Total megabits = bitrate (Mbps) x duration in seconds
  • Megabytes = total megabits / 8
  • Gigabytes = megabytes / 1024

Each audio track adds about 2.3 Mbps to the bitrate before those steps run.

Worked examples

Format Bitrate Duration File size
4K24 (XAVC S) 100 Mbps 10 min 7.32 GB
4K60 (XAVC S-I) 600 Mbps 5 min 21.97 GB
8K RAW 2600 Mbps 2 min 38.09 GB

How it works

Select your camera preset or enter a custom bitrate.

Set your recording duration (hours and minutes).

Choose your SD card size.

See exactly how many clips fit on your card.

Why it matters

Running out of storage mid-shoot is expensive. This calculator tells you exactly how much footage you can capture based on your camera's bitrate and your card capacity. No more guessing.

Pro Tip

Audio tracks add ~2.3 Mbps each. If you're recording multi-channel audio, factor that in for accurate calculations.

Storage Usage
0 GB / 128 GB
File Size
0 GB
Clips Per Card
0

Questions people ask

How do I calculate video file size from bitrate?

Multiply the bitrate in Mbps by the recording time in seconds to get total megabits, divide by 8 to get megabytes, then divide by 1024 to get gigabytes. A 100 Mbps clip recorded for 10 minutes is 100 x 600 / 8 / 1024, which comes to about 7.32 GB.

Does higher bitrate mean better video quality?

Usually yes, at the same codec and resolution: more bitrate means more data per second, so less compression and fewer artifacts. But bitrate is not the whole story. A modern codec like H.265 or an intra-frame format like XAVC S-I can look better at a lower bitrate than an older codec running higher, and the payoff shrinks past the point your sensor and lens can resolve.

How much does audio add to the file size?

This calculator assumes about 2.3 Mbps per audio track, which is added to the video bitrate before the file size math runs. Two tracks add roughly 4.6 Mbps. On a high-bitrate 4K or 8K clip the audio is a rounding error, but on a low-bitrate proxy or a long interview it can be worth counting.