Data storage converter (decimal and binary)

Bytes, kB/MB/GB/TB (decimal) and KiB/MiB/GiB/TiB (binary), plus bits, kilobits, megabits and gigabits.

Fromgigabyte (1000³ B) (GB)

Togibibyte (1024³ B) (GiB)

0.9313225746

DecimalsAuto (up to 10 significant digits)

Formula: GiB = GB × 0.931322574615

1 GB = 0.9313225746 GiB

Common values: gigabyte (1000³ B) to gibibyte (1024³ B)

GB	GiB
1 GB	0.9313225746 GiB
2 GB	1.862645149 GiB
4 GB	3.725290298 GiB
8 GB	7.450580597 GiB
16 GB	14.90116119 GiB
32 GB	29.80232239 GiB
64 GB	59.60464478 GiB
128 GB	119.2092896 GiB
256 GB	238.4185791 GiB
512 GB	476.8371582 GiB
1,000 GB	931.3225746 GiB

How it works

Two systems of prefixes are in use for data. Decimal (SI) prefixes step by 1000: 1 kB = 1000 bytes, 1 MB = 1000² bytes, 1 GB = 1000³ bytes. Binary (IEC 80000-13) prefixes step by 1024: 1 KiB = 1024 bytes, 1 MiB = 1024² bytes, 1 GiB = 1024³ bytes. The unit picker lists them in separate groups so you never mix them by accident.

Drive manufacturers, network speeds and macOS use decimal units. Windows and many upload forms compute in binary but still write "KB" and "GB", which is why a 1 TB drive shows as about 931 GB in Windows Explorer: 10¹² bytes ÷ 1024³ = 931.32 GiB. Nothing is missing; the same bytes are counted with a different divisor. The gap grows with each prefix: 2.4% at kilo, 4.9% at mega, 7.4% at giga, 10% at tera.

Network speeds are quoted in bits per second. Divide by 8 to get bytes: a 100 Mbit/s connection moves at most 12.5 MB/s before protocol overhead.

Common data storage conversions

Drive makers use decimal units (1 GB = 1,000,000,000 bytes) while many operating systems report binary units (1 GiB = 1,073,741,824 bytes), which is why a "1 TB" drive shows about 931 GiB. Network speeds are in bits, file sizes in bytes (8 bits).

1 GB = 0.9313225746 GiB (GiB = GB × 0.931322574615)
1 TB = 0.9094947018 TiB (TiB = TB × 0.909494701773)
1 MB = 0.9536743164 MiB (MiB = MB × 0.953674316406)
1 Mbit = 0.125 MB (MB = Mbit × 0.125)
1 Gbit = 125 MB (MB = Gbit × 125)
1 GiB = 1.073741824 GB (GB = GiB × 1.073741824)

Every data storage unit in this converter

The size of each unit in bytes (B), the base unit the converter uses internally. Values are exact where the unit has an exact definition.

Unit	In B	System
bit (bit)	0.125 B	Bits
kilobit (1000 bits) (kbit)	125 B	Bits
megabit (10⁶ bits) (Mbit)	125,000 B	Bits
gigabit (10⁹ bits) (Gbit)	125,000,000 B	Bits
byte (B)	1 B	Decimal (SI): powers of 1000
kilobyte (1000 B) (kB)	1,000 B	Decimal (SI): powers of 1000
megabyte (1000² B) (MB)	1,000,000 B	Decimal (SI): powers of 1000
gigabyte (1000³ B) (GB)	1,000,000,000 B	Decimal (SI): powers of 1000
terabyte (1000⁴ B) (TB)	1,000,000,000,000 B	Decimal (SI): powers of 1000
petabyte (1000⁵ B) (PB)	1e+15 B	Decimal (SI): powers of 1000
kibibyte (1024 B) (KiB)	1,024 B	Binary (IEC): powers of 1024
mebibyte (1024² B) (MiB)	1,048,576 B	Binary (IEC): powers of 1024
gibibyte (1024³ B) (GiB)	1,073,741,824 B	Binary (IEC): powers of 1024
tebibyte (1024⁴ B) (TiB)	1,099,511,628,000 B	Binary (IEC): powers of 1024
pebibyte (1024⁵ B) (PiB)	1.125899907e+15 B	Binary (IEC): powers of 1024

How to use it

Choose the unit you have, checking whether it is decimal (MB) or binary (MiB).
Choose the unit you want and type the size in either box.
Use the table for common drive and memory sizes.

Frequently asked questions

Why does my 1 TB drive show only 931 GB?

The drive holds 1,000,000,000,000 bytes. Windows divides by 1024³ and labels the result GB, giving 931.3; those are really GiB. The capacity is the same.

Is 1 MB 1000 KB or 1024 KB?

By the SI and IEC standards, 1 MB = 1000 kB and 1 MiB = 1024 KiB. In casual use and in Windows, "MB" often means MiB. When a limit matters, assume the smaller figure.

How do I convert Mbps to MB/s?

Divide by 8: 1 byte = 8 bits. 200 Mbit/s = 25 MB/s. Real downloads are a little slower because of protocol overhead.

What does an upload limit of "2 MB" mean?

It may be 2,000,000 bytes or 2,097,152 bytes (2 MiB); sites rarely say which. Aim for a file below 2,000,000 bytes to be safe; the image compressors on this site do that automatically.