Data storage converter

Convert GB to MB, TB to GB and GiB to GB with decimal (kB, MB, GB, TB) and binary (KiB, MiB, GiB, TiB) prefixes kept apart, plus bits and bytes.

By Admin Drafted with AI writing toolsUpdated 2 November 2026Checked examples: 5

Converted value

Significant figures: 12; Nearest, ties away from zero

Conversion: 1 GiB = 1,073.741824 MB
Conversion factor: 1,073.741824
Exactness: Exact

1 GiB is exactly 1,073.741824 MB.

How much larger each binary prefix is than its decimal twin

1 GiB in every Data storage unit Rows: 25

Unit	Value	Definition
bit	8,589,934,592	Base unit
nibble	2,147,483,648	1 nibble = 4 bit, exact
byte (B)	1,073,741,824	1 B = 8 bit, exact
kilobyte (kB)	1,073,741.824	1 kB = 8,000 bit, exact
megabyte (MB)	1,073.741824	1 MB = 8,000,000 bit, exact
gigabyte (GB)	1.073741824	1 GB = 8,000,000,000 bit, exact
terabyte (TB)	0.001073741824	1 TB = 8,000,000,000,000 bit, exact
petabyte (PB)	0.000001073741824	1 PB = 8 × 10¹⁵ bit, exact
exabyte (EB)	1.073741824 × 10⁻⁹	1 EB = 8 × 10¹⁸ bit, exact
zettabyte (ZB)	1.073741824 × 10⁻¹²	1 ZB = 8 × 10²¹ bit, exact
yottabyte (YB)	1.073741824 × 10⁻¹⁵	1 YB = 8 × 10²⁴ bit, exact
kibibyte (KiB)	1,048,576	1 KiB = 8,192 bit, exact
mebibyte (MiB)	1,024	1 MiB = 8,388,608 bit, exact
gibibyte (GiB)	1	1 GiB = 8,589,934,592 bit, exact
tebibyte (TiB)	0.0009765625	1 TiB = 8,796,093,022,208 bit, exact
pebibyte (PiB)	9.536743 × 10⁻⁷	1 PiB = 9.007199254740992 × 10¹⁵ bit, exact
exbibyte (EiB)	9.313226 × 10⁻¹⁰	1 EiB = 9.223372036854775808 × 10¹⁸ bit, exact
zebibyte (ZiB)	9.094947 × 10⁻¹³	1 ZiB = 9.4447329657392904274 × 10²¹ bit, exact
yobibyte (YiB)	8.881784197 × 10⁻¹⁶	1 YiB = 9.6714065569170333976 × 10²⁴ bit, exact
kilobit (kbit)	8,589,934.592	1 kbit = 1,000 bit, exact
megabit (Mbit)	8,589.934592	1 Mbit = 1,000,000 bit, exact
gigabit (Gbit)	8.589934592	1 Gbit = 1,000,000,000 bit, exact
terabit (Tbit)	0.008589934592	1 Tbit = 1,000,000,000,000 bit, exact
kibibit (Kibit)	8,388,608	1 Kibit = 1,024 bit, exact
mebibit (Mibit)	8,192	1 Mibit = 1,048,576 bit, exact

How it's calculated S

Convert gibibyte to bit
$1\ \text{GiB} \times 8{,}589{,}934{,}592\ \tfrac{\text{bit}}{\text{GiB}} = 8{,}589{,}934{,}592\ \text{bit}$
1 GiB = 8,589,934,592 bit, exact
Convert bit to megabyte
$8{,}589{,}934{,}592\ \text{bit} \div 8{,}000{,}000\ \tfrac{\text{bit}}{\text{MB}} = 1{,}073.741824\ \text{MB}$
1 MB = 8,000,000 bit, exact
Combined factor
$1\ \text{GiB} = \frac{8{,}589{,}934{,}592}{8{,}000{,}000}\ \text{MB} = 1{,}073.741824\ \text{MB}$
Both units are defined exactly and the converted mathematical value has a terminating decimal. A displayed result may still be rounded.

About the data storage converter

Data sizes use two sets of prefixes. The decimal ones follow the SI: 1 kB = 1,000 bytes, 1 MB = 10⁶ and 1 GB = 10⁹ bytes. The binary ones, approved by the IEC in December 1998 and now part of IEC 80000-13, step by 1,024: 1 KiB = 1,024 bytes, 1 MiB = 2²⁰ and 1 GiB = 2³⁰ bytes. A byte is 8 bits, and every conversion between these units is exact.

The default converts 1 GiB to 1,073.741824 MB. The same gap explains why a new drive looks smaller: a 1 TB drive holds 10¹² bytes, which software counting in binary units shows as 931.32 GiB, often labelled “931 GB”.

The gap grows with each prefix: 2.4% at kilo, 7.37% at giga, 9.95% at tera and 20.9% at yotta. Memory chips come in powers of two, so RAM sizes are binary even when written GB, while drive makers and network speeds use decimal prefixes.

How to convert KB to MB, GB and TB

Each step up from kB to MB, GB and TB divides by 1,000, and each step down multiplies by 1,000. So 2,500 kB = 2.5 MB, 1 MB = 1,000 kB and 1 TB = 1,000 GB. Binary units step by 1,024 instead: 1,024 KiB = 1 MiB.

To skip several prefixes, apply the factor once per step. Kilobytes to gigabytes is two steps, so divide by 1,000,000: 5,000,000 kB is 5 GB. In binary, 1 GiB is 1,024 × 1,024 = 1,048,576 KiB.

Is a kilobyte 1,000 or 1,024 bytes?

Both definitions are in use, with different symbols. Decimal SI prefixes count in powers of 1,000: 1 kB is 1,000 bytes and 1 MB is 1,000,000 bytes (NIST SI prefixes).

Binary IEC prefixes count in powers of 1,024 and add an i: 1 KiB is 1,024 bytes and 1 MiB is 1,048,576 bytes (NIST binary prefixes).

The confusion comes from software that shows binary sizes under decimal labels. Windows reports 1,024-byte units as KB, MB and GB, while drive makers and network specifications use the decimal meaning.

When a figure could be either, check where it came from, then pick the unit that matches. A drive label or a macOS file size is decimal; a RAM size or a Windows file size is binary.

Kilobytes vs kilobits

A capital B means bytes and a lower-case b means bits, and one byte is 8 bits. A search for "kb to MB" can mean two different conversions:

1 kB (kilobyte) = 0.001 MB.
1 kbit (kilobit) = 0.000125 MB, because 1,000 bits are 125 bytes.
1 MB = 1,000 kB = 8,000 kbit.

File sizes are counted in bytes and network speeds in bits per second. A 100 Mbit/s connection therefore moves at most 12.5 MB each second.

Data storage conversion chart

All values are exact.

Entered amount	To unit	Exact value
1 kB	MB	0.001
1000 kB	MB	1
2500 kB	MB	2.5
1 MB	kB	1000
1 kbit	MB	0.000125
1 MB	kbit	8000
1 kbit	Mbit	0.001
1 KiB	MiB	0.0009765625
1024 KiB	MiB	1
1 MiB	KiB	1024
1 GB	MB	1000
1 GiB	MiB	1024
1 GiB	MB	1073.741824
1 TB	GB	1000
1 TB	GiB	931.322574615478515625
1 TiB	GB	1099.511627776
1 B	bit	8
1 bit	B	0.125

Bytes in each unit

Unit	Bytes in one unit
kB	1000
KiB	1024
MB	1000000
MiB	1048576
GB	1000000000
GiB	1073741824
TB	1000000000000
TiB	1099511627776
PB	1000000000000000
PiB	1125899906842624
EB	1000000000000000000
EiB	1152921504606846976
ZB	1000000000000000000000
ZiB	1180591620717411303424
YB	1000000000000000000000000
YiB	1208925819614629174706176

To convert between any two units, divide the bytes in the first by the bytes in the second. For GiB to MB: 1,073,741,824 ÷ 1,000,000 = 1,073.741824, so 1 GiB is 1,073.741824 MB.

Drive sizes, RAM and upload limits

A drive sold as 1 TB holds 1,000,000,000,000 bytes. Divided by 1,073,741,824 bytes per GiB, that is 931.32 GiB, which Windows displays as about 931 GB.

Nothing is lost in that conversion. Formatting, recovery partitions and preinstalled files account for any space missing beyond it.

Memory is sold in binary sizes even when it is labeled GB. A 16 GB RAM module holds 16 GiB, or 17,179,869,184 bytes.

Upload limits need the same care. A 2,050 kB file (2.05 MB) is over a 2 MB limit but under a 2 MiB one, because 2 MiB is 2,097,152 bytes.

Typing units with the number

You can type a unit symbol after the number, and case matters:

kB and KB are kilobytes; kb is a kilobit.
MB is a megabyte; Mb is a megabit.
A unit typed with the number, as in 1 MB, takes priority over the selected unit.
Speeds such as 100 Mbps or 1 MB/s are rates, not sizes; use the data transfer rate converter.

Common mistakes

Writing 1 GB = 1,024 MB. Either 1 GB = 1,000 MB or 1 GiB = 1,024 MiB. Mixing the two puts a 1 GiB file at 1,024 MB when it is 1,073.741824 MB, about 4.9% off.
Forgetting the factor of 8. A 1 GB download over a 100 Mbit/s line is 8,000 Mbit, so it takes at least 80 seconds, not 10. The download time calculator does this arithmetic.
Comparing a decimal limit with a binary size. Convert both figures to the same convention before deciding whether a file fits.

For a single pair, see MB to GB, GB to MB or TB to GB. The SI prefix converter covers the same prefixes on other units.

Worked examples

1 GiB in MB

Value: 1 GiB
From: gibibyte (GiB)
To: megabyte (MB)

Converted value: 1,073.741824 MB
Exactness: Exact

Checked against: 2³⁰ bytes = 1,073,741,824 bytes (IEC 80000-13); ÷ 10⁶

A 1 TB drive in GiB

Value: 1 TB
From: terabyte (TB)
To: gibibyte (GiB)

Converted value: 931.322574615 GiB

Checked against: 10¹² / 2³⁰ = 244140625/262144, a terminating decimal

1 KiB in kB

Value: 1 KiB
From: kibibyte (KiB)
To: kilobyte (kB)

Converted value: 1.024 kB

Checked against: 1024 bytes / 1000 bytes

Largest gap: 1 YiB in YB

Value: 1 YiB
From: yobibyte (YiB)
To: yottabyte (YB)

Converted value: 1.20892581961 YB

Checked against: 2⁸⁰ / 10²⁴ = 1.208925819614629174706176 exactly

Questions

Why does my 1 TB drive show only 931 GB?

Because the maker and the operating system count differently. The drive's 1 TB is 10¹² bytes; Windows divides by 2³⁰ and shows 931.32 while labelling it GB. Nothing is missing, since 10¹² ÷ 1,073,741,824 ≈ 931.32; formatting and recovery partitions take a little more. macOS has counted in decimal since OS X 10.6 and shows the same drive as 1 TB.

Is 1 GB 1,000 MB or 1,024 MB?

Under the SI and IEC 80000-13, 1 GB is exactly 1,000 MB (10⁹ bytes), and the binary unit is 1 GiB = 1,024 MiB (2³⁰ bytes). Drive makers and macOS use the decimal meaning; RAM and Windows use the binary one while writing GB. The “1.44 MB” floppy disk mixed the two: 1,440 × 1,024 bytes.

How many bits are in a byte?

Eight. IEC 80000-13 defines the byte as 8 bits, also called an octet. File sizes are counted in bytes (B) and network speeds in bits per second (bit/s), so a 100 Mbit/s connection moves at most 12.5 MB per second; a capital B marks bytes.

What is a GiB?

A gibibyte, 2³⁰ = 1,073,741,824 bytes. The IEC created the binary prefixes kibi, mebi, gibi and tebi so that kilo, mega and giga could keep their SI meanings of 10³, 10⁶ and 10⁹. Many Linux tools and technical specifications use GiB; Windows shows the same quantity labelled GB.

How many GB are in 1 TB?

1,000 GB in decimal units, which is how drives are sold. In binary units 1 TiB is 1,024 GiB, and a decimal 1 TB is 931.32 GiB. The converter keeps TB, TiB, GB and GiB separate, so you can see that 1 TiB is 1,099.51 GB, about 10% more than 1 TB.

About this calculator

\begin{gathered} x_{\text{to}} = x_{\text{from}} \times \dfrac{f_{\text{from}}}{f_{\text{to}}} \\ f = \text{one unit expressed in } \text{bit} \end{gathered}

Sources

Checked against references

This calculator includes 5 worked examples with independently sourced answers. They run in the test suite, and you can run them here too.

Put this calculator on your site

Paste this where you want the calculator to appear. It is free to use, it stays in step with corrections made here, and the credit line below it links back so your readers can find the full version.

Height

<iframe src="https://www.calcopenly.com/conversion/data-storage-converter?embed=1"
        title="Data storage converter by CalcOpenly"
        width="100%" height="820" loading="lazy"
        style="border:1px solid #d9dee2;border-radius:12px;max-width:680px"></iframe>
<p style="font:14px/1.6 system-ui,sans-serif;margin:.5rem 0 0">
  <a href="https://www.calcopenly.com/conversion/data-storage-converter">Data storage converter</a> by <a href="https://www.calcopenly.com/">CalcOpenly</a>
</p>

Preview the embed

Keep the credit line. It is the only condition, and it is what keeps these calculators free.