About this tool
Convert storage and data sizes across bits, bytes and both families of larger units: decimal (KB, MB, GB, TB — powers of 1,000) and binary (KiB, MiB, GiB, TiB — powers of 1,024). All equivalents are shown side by side.
The two families exist because marketing and operating systems disagree. Drive makers use decimal units (1 TB = 10¹² bytes); Windows historically reports binary units while labeling them GB — which is exactly why a “1 TB” drive shows up as about 931 GB. The IEC standardized the KiB/MiB/GiB names in 1998 to end the ambiguity, with partial success.
How to use it
- Enter a value and pick its unit.
- Read the value in every other unit, decimal and binary.
- Use the GB ↔ GiB pair to explain disk-size discrepancies.
Frequently asked questions
Why does my 1 TB drive show only 931 GB?
The drive holds 1,000,000,000,000 bytes (decimal TB). Your OS divides by 1,024³ and shows binary gibibytes: ≈ 931.3 GiB, often labeled GB.
How many bits in a byte?
Eight, on every modern system. Network speeds are quoted in bits per second, storage in bytes — a 100 Mbps connection moves at most 12.5 MB/s.
What is a kibibyte?
KiB = 1,024 bytes exactly, the IEC binary unit. KB officially means 1,000 bytes, though casual usage still mixes them.