With this app, you can calculate each bitrate, time length and file size from other two items.
- Filesize / Bitrate (transfer speed) = Length (transfer time)
- Bitrate * Length = Filesize
- Filesize / Length = Bitrate
- and filesize SI prefix (KB, MB, GB, etc..) to/from binary prefix (KiB, MiB, GiB, ...) converter.

You can use this app when you want to know...
- how long does it take to backup 200GB data with USB2.0 HDD.
- how much data will be transferred if you watch a 720P youtube video 30 minutes.
- what is the maximum bitrate you can use to encode a 100MB, 30minutes video.
- how many terabytes you can actually use with 3TB HDD.

About Unit
With bitrate, units are always SI prefix (1kbps = 1000bps, 1Mbps = 1000kbps). As for file size, you can use both the SI prefix and binary prefix (1KiB = 1024 bytes, 1MiB = 1024KiB). If you are using Windows, Explorer's "KB" equals this app's "KiB". If you are using Mac or Ubuntu, its "KB" equals this app's "KB".