Data size converter.

Enter a size and see it in decimal (KB, MB, GB, TB — powers of 1000) and binary (KiB, MiB, GiB, TiB — powers of 1024) at once. The two side by side make the “why is my 1TB drive only 931GB” confusion finally obvious.

The same size, two definitions

Almost every “missing space” mystery and surprise bandwidth bill traces back to one fact: a GB can mean 1,000,000,000 bytes or 1,073,741,824 bytes depending on who is counting. Storage vendors and network bills use decimal; operating systems and RAM use binary but often borrow the decimal label. The gap is about 7% at GB and grows with scale. Seeing both columns at once turns a confusing discrepancy into an obvious, expected one — and reminds you to write GiB when you mean GiB.