Data Size Converter (MB, GB, MiB, GiB…)

Convert digital storage between bits, bytes, and decimal (kB, MB, GB, TB) and binary (KiB, MiB, GiB, TiB) units — one value into every unit, with a reference table.

Bit (bit)–

Byte (B)–

Kilobyte (decimal) (kB)–

Megabyte (decimal) (MB)–

Gigabyte (decimal) (GB)–

Terabyte (decimal) (TB)–

Kibibyte (binary) (KiB)–

Mebibyte (binary) (MiB)–

Gibibyte (binary) (GiB)–

Tebibyte (binary) (TiB)–

Data size reference

1 unit	B	MB	MiB	GB
1 bit	0.125	0.000000125	0.000000119209	0.000000000125
1 B	1	0.000001	0.000000953674	0.000000001
1 kB	1 000	0.001	0.000953674	0.000001
1 MB	1 000 000	1	0.953674	0.001
1 GB	1 000 000 000	1 000	953.674	1
1 TB	1 000 000 000 000	1 000 000	953 674	1 000
1 KiB	1 024	0.001024	0.000976563	0.000001024
1 MiB	1 048 580	1.04858	1	0.00104858
1 GiB	1 073 740 000	1 073.74	1 024	1.07374
1 TiB	1 099 510 000 000	1 099 510	1 048 580	1 099.51

Converting digital storage units

Digital storage is counted in bits and bytes (8 bits make a byte), but the larger units come in two flavours that are easy to mix up. This converter shows both and lets you move between them.

Decimal vs binary — the source of confusion

Decimal units step by 1000: 1 kB = 1000 B, 1 MB = 1 000 000 B, and so on. Binary units step by 1024 and are spelled with an "i": 1 KiB = 1024 B, 1 MiB = 1 048 576 B. Storage makers quote decimal (a "1 TB" drive is 10¹² bytes), while operating systems often report binary — which is why that 1 TB drive shows up as about 931 GiB and seems "smaller" than advertised. Nothing is missing; the two just count differently.

Worked example

A 500 GB SSD is 500 × 10⁹ = 5×10¹¹ bytes. In binary units that's 500×10⁹ / 1024³ ≈ 465.7 GiB — the figure your computer is likely to show. Network speeds, by contrast, are usually in bits: a "100 Mb/s" link moves 100 / 8 = 12.5 MB per second.

Estimating a device's monthly cellular usage instead? See theIoT data usage calculator.

Common questions

Is a megabyte 1,000 or 1,024 kilobytes?: Both, depending on who is speaking — and that ambiguity is the entire problem. A megabyte (MB) is officially 1,000,000 bytes, using decimal prefixes like every other SI unit. A mebibyte (MiB) is 1,048,576 bytes, which is 2²⁰. Operating systems have historically shown the binary figure while labelling it MB, which is where the confusion comes from. This converter keeps the two families separate rather than pretending they are interchangeable.
Why does my 1 TB drive show as only 931 GB?: Nothing is missing — you are seeing the same number described two ways. The manufacturer sells 1 TB meaning 1,000,000,000,000 bytes. Your operating system divides that by 1024 three times and displays 931.3, but labels the result "GB" when it is really 931.3 GiB. The drive holds exactly what was advertised; only the label is inconsistent.
Why are internet speeds in megabits rather than megabytes?: Network speeds are quoted in bits per second and file sizes in bytes, and there are 8 bits to a byte. So a 100 Mbps connection downloads at roughly 12.5 MB/s at best. The convention is historical — data links have always been measured in bits — but it means the number on your broadband contract is about eight times larger than the download speed you will see, which is not an accident nobody noticed.
When should I use MiB rather than MB?: Use the binary units (KiB, MiB, GiB) when the quantity is genuinely a power of two — memory sizes, block sizes, buffer allocations. Use decimal units (KB, MB, GB) for storage capacity, file sizes and anything quoted commercially. If you are reading a figure someone else produced and it matters, check which one they meant; a 7% error at the gigabyte level compounds to 10% at terabyte scale.