Zettabyte data size converter

Value

Unit

Unit	Decimal (1000-based)	Binary (1024-based)

Decimal and binary are genuinely different numbers. A storage manufacturer's gigabyte is 1,000,000,000 bytes; an operating system often reports a "gigabyte" as 1,073,741,824 bytes (strictly a GiB). Both are shown, clearly labelled, rather than picking one silently.

Every unit up to zettabytes

Type a value into any unit, from a single byte up to a zettabyte (10²¹ bytes, roughly the scale of all data expected to exist worldwide), and every other unit updates with it - bit, byte, kilobyte, megabyte, gigabyte, terabyte, petabyte, exabyte, zettabyte.

Decimal and binary are genuinely different numbers

This is the single most common source of a "missing" gigabyte. A storage manufacturer's gigabyte is 1,000,000,000 bytes (decimal, SI units), but an operating system often reports storage using 1,073,741,824 bytes as a "gigabyte" (binary, strictly GiB). A 1,000,000,000,000-byte drive is honestly labelled 1 TB by the manufacturer and shows as roughly 931 GB in an OS that uses binary units for the same label - not a defect in the drive, a mismatch in which gigabyte is meant. Both conversions are shown here, side by side and clearly labelled, rather than picking one silently.

Bits versus bytes

Network speeds are conventionally quoted in bits per second (Mbps) while file sizes are quoted in bytes (MB) - an 8x difference that catches out anyone estimating a download time from a connection speed. Both are included as units here for exactly that reason.