File Size Converter
Convert a file size to every unit at once — decimal (KB, MB, GB) and binary (KiB, MiB, GiB).
Last updated
About this tool
"Decimal" units (KB, MB, GB, TB) step by 1,000 and are what storage manufacturers advertise and what the SI system defines — a 1 TB drive is 1,000,000,000,000 bytes. "Binary" units (KiB, MiB, GiB, TiB) step by 1,024 and are what operating systems typically show you (macOS switched to decimal reporting some years back; Windows still generally uses binary math but labels it with decimal unit names, which is the single biggest source of "my drive shows less space than advertised" confusion). This tool keeps the two systems clearly separate so you can see both at once.
Nothing you enter here is sent to a server — the entire tool runs as JavaScript in your browser tab.