Convert between every common unit of data — bits, bytes, decimal (KB) and binary (KiB).
Storage manufacturers (and hard drives) use decimal units: 1 KB = 1,000 B, 1 GB = 1,000,000,000 B. Operating systems (Windows, Linux) often use binary units: 1 KiB = 1,024 B, 1 GiB = 1,073,741,824 B. The discrepancy is why a "1 TB" hard drive shows up as ~931 GB in Windows.