Data Storage Converter (MB, GB, TB)

Convert data sizes: bits, bytes, KB, MB, GB, TB and binary KiB, MiB, GiB, TiB.

Is a gigabyte 1000 or 1024 megabytes?

Both are used: a gigabyte (GB) is officially 1,000,000,000 bytes, while a gibibyte (GiB) is 1,073,741,824 bytes (1024³). Drive makers use GB; Windows reports GiB but labels it "GB", which is why a 1 TB drive shows about 931 "GB".

Decimal vs binary units

Decimal (SI)	Binary (IEC)
1 KB = 1,000 bytes	1 KiB = 1,024 bytes
1 MB = 1,000² bytes	1 MiB = 1,024² bytes
1 GB = 1,000³ bytes	1 GiB = 1,024³ bytes
1 TB = 1,000⁴ bytes	1 TiB = 1,024⁴ bytes

Bits and bytes

Internet speeds are in bits (Mbit/s), file sizes in bytes. One byte is 8 bits, so a 100 Mbit/s connection downloads at most 12.5 MB per second.

Frequently asked questions

Why does my 1 TB drive show 931 GB?

The drive has 1,000,000,000,000 bytes, which is 931 GiB — shown by Windows as "GB".

How many MB is 1 GB?

1,000 MB, or 953.67 MiB.

How long will a 1 GB download take?

At 100 Mbit/s, about 80 seconds (8,000 Mbit ÷ 100).