File size converter
Type a size like 1.5 GB or 750 MiB and see it in SI and binary units, in bytes and in bits. Find out why a 1 TB drive shows 931 GB.
B is a byte and b is a bit. With no unit, it is bytes.
SI (powers of 1000)
Binary (powers of 1024)
- Exact bytes
- 1,000,000,000,000 B
- Bits
- 8,000,000,000,000 b
A 1 TB drive holds 1,000,000,000,000 bytes, about 931 GiB: that is why Windows shows 931 "GB".
How it works
How it works
Type a size with its unit, like 1.5 GB, 750 MiB or 100 Mb. A number with no unit is bytes. You immediately get the size in every International System unit (kB, MB, GB…, powers of 1000) and every binary unit (KiB, MiB, GiB…, powers of 1024), plus the exact bytes, the bits and the readable form in each system.
Case matters: B is a byte and b is a bit, so 100 Mb (megabits, like your broadband speed) is 12.5 MB. KB with a capital K is read as the SI kB, but keep in mind that Windows writes KB, MB and GB while actually computing KiB, MiB and GiB.
The 931 GB mystery
Drive makers use SI: 1 TB is 1,000,000,000,000 bytes. Windows divides by 1024 three times and shows about 931 “GB”, which are 931 GiB. macOS and Linux usually use SI and show 1 TB. No space is missing: they are two ways of counting the same number of bytes.
FAQ
Why does my 1 TB drive show less space?
The maker counts 1 TB as 1,000,000,000,000 bytes (SI). Windows divides by 1024 and shows about 931 "GB", which are really GiB. No space is missing: they are two ways of counting.