How many MB are in a GB?

1,000 MB in a decimal gigabyte (GB). In binary units, 1 GiB is 1,024 MiB. Software that says 1 GB = 1,024 MB is using the name GB for the binary unit.

What is the difference between GB and GiB?

1 GB is 10⁹ = 1,000,000,000 bytes and 1 GiB is 2³⁰ = 1,073,741,824 bytes. A GiB is 7.37% larger: 1 GiB is 1.073741824 GB and 1 GB is 0.9313225746 GiB.

Why does my 1 TB drive show about 931 GB?

The drive holds 1,000,000,000,000 bytes, which is 931.3225746 GiB. Software that counts in 1,024s shows that number, sometimes with the label GB.

How many bytes are in a kilobyte?

1,000 bytes in a kilobyte (KB), the SI meaning of kilo, and 1,024 bytes in a kibibyte (KiB).

How many MB per second is a 100 Mbps connection?

12.5 MB per second: 100 megabits ÷ 8 bits per byte. A 1 Gbit/s line carries 125 MB per second, before protocol overhead.

Data Storage Converter

Convert bytes, KB, MB, GB, TB and bits, with decimal SI units (1 GB = 1,000 MB) kept apart from binary IEC units (1 GiB = 1,024 MiB). How it works

From

From unit

To unit

Converted to Megabytes

1000

1 Gigabyte = 1000 Megabytes

Gigabytes to Megabytes

Gigabytes	Megabytes
1	1000
2	2000
5	5000
10	10000
100	100000
1,000	1000000

Decimal and binary units side by side

Size in bytes of each decimal (SI) and binary (IEC) unit, and how much larger the binary unit is
Decimal (SI)	Bytes	Binary (IEC)	Bytes	Binary is larger by
KB	1,000	KiB	1,024	2.4%
MB	1,000,000	MiB	1,048,576	4.86%
GB	1,000,000,000	GiB	1,073,741,824	7.37%
TB	1,000,000,000,000	TiB	1,099,511,627,776	9.95%
PB	1,000,000,000,000,000	PiB	1,125,899,906,842,624	12.59%
EB	1,000,000,000,000,000,000	EiB	1,152,921,504,606,846,976	15.29%

1 byte is 8 bits. Network speeds are usually quoted in bits (kbit, Mbit, Gbit, decimal), file sizes in bytes. 1 GiB is 1.073741824 GB.

About the Data Storage Converter

1 GB is 1,000 MB, or 1,000,000,000 bytes, while 1 GiB is 1,024 MiB, or 1,073,741,824 bytes, 7.37% more. KB, MB and GB are decimal SI units that count in 1,000s; KiB, MiB and GiB are the binary IEC units that count in 1,024s, and this converter keeps the two families apart. The gap widens at each prefix, because the ratio is multiplied by 1.024 again at every step: a TiB is 9.95% larger than a TB.

Advertised drive sizes in binary units

Sold as	Bytes	GiB	TiB
256 GB	256000000000	238.4185791	0.2328306437
500 GB	500000000000	465.6612873	0.4547473509
512 GB	512000000000	476.8371582	0.4656612873
1 TB	1000000000000	931.3225746	0.9094947018
2 TB	2000000000000	1862.645149	1.818989404
4 TB	4000000000000	3725.290298	3.637978807

Drive makers count in decimal units. Software that counts in 1,024s shows the same bytes as the smaller GiB figure, and formatting takes some space as well.

Line speeds in bytes per second

Line speed	MB per second	MiB per second
10 Mbit/s	1.25	1.192092896
100 Mbit/s	12.5	11.92092896
1000 Mbit/s (1 Gbit/s)	125	119.2092896

Bytes are 8 bits. Real downloads are slower than the line speed because of protocol overhead.

Frequently asked questions

How many MB are in a GB?: 1,000 MB in a decimal gigabyte (GB). In binary units, 1 GiB is 1,024 MiB. Software that says 1 GB = 1,024 MB is using the name GB for the binary unit.
What is the difference between GB and GiB?: 1 GB is 10⁹ = 1,000,000,000 bytes and 1 GiB is 2³⁰ = 1,073,741,824 bytes. A GiB is 7.37% larger: 1 GiB is 1.073741824 GB and 1 GB is 0.9313225746 GiB.
Why does my 1 TB drive show about 931 GB?: The drive holds 1,000,000,000,000 bytes, which is 931.3225746 GiB. Software that counts in 1,024s shows that number, sometimes with the label GB.
How many bytes are in a kilobyte?: 1,000 bytes in a kilobyte (KB), the SI meaning of kilo, and 1,024 bytes in a kibibyte (KiB).
How many MB per second is a 100 Mbps connection?: 12.5 MB per second: 100 megabits ÷ 8 bits per byte. A 1 Gbit/s line carries 125 MB per second, before protocol overhead.

When two sizes for the same thing disagree

Use it when two numbers for the same size disagree: a 1 TB drive that a computer counting in 1,024s shows as 931 GiB, a cloud bill in GB against a quota in GiB, or a 100 Mbit/s line that downloads 12.5 MB a second. Decimal units (KB, MB, GB) and binary units (KiB, MiB, GiB) sit in separate groups, and one toggle switches every byte unit to the other family. Under the result, a table converts 1, 2, 5, 10, 100 and 1,000 of the first unit into the second: 1,000 GB is 931.3225746 GiB.

Decimal and binary prefixes

Every unit is a whole number of bytes: bytes = amount × unit size, then result = bytes ÷ target unit size.

Decimal (SI): 1 KB = 1,000 bytes, 1 MB = 1,000,000, 1 GB = 10⁹, up to 1 EB = 10¹⁸.
Binary (IEC): 1 KiB = 1,024 bytes, 1 MiB = 1,048,576, 1 GiB = 2³⁰ = 1,073,741,824, up to 1 EiB = 2⁶⁰.
Bits: 1 byte = 8 bits; kbit, Mbit, Gbit and Tbit are decimal.

Example: 1 TB = 1,000,000,000,000 bytes ÷ 1,073,741,824 = 931.3225746 GiB.

Whole-number results show every digit (1 TiB = 1099511627776 bytes); other results show 10 significant digits (at least 2 decimals), and anything below 0.000000001 shows as < 0.000000001. Negative sizes get a message.

Fun Fact: The binary prefixes kibi, mebi and gibi are younger than most people expect: the IEC approved them in December 1998, after years in which computer makers used kilo for 1,024 although the SI defines it as 1,000.