By Tim King · Updated 19 September 2026

GB to GiB and GiB to GB Converter

Decimal Gigabytes vs Binary Gibibytes, Why a 1 TB Drive Shows 931 GB

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gigabytes to gibibytes formula

GiB = GB × 10⁹ ÷ 2³⁰

1 gigabyte = 0.9313225746 gibibytes, so multiply gigabytes by 0.9313225746. Going the other way, 1 gibibyte = 1.073741824 gigabytes.

gigabytes to gibibytes table

gigabytes (GB)	gibibytes (GiB)
1	0.931323
2	1.86265
4	3.72529
8	7.45058
16	14.9012
32	29.8023
50	46.5661
64	59.6046
100	93.1323
120	111.759
128	119.209
240	223.517
250	232.831
256	238.419
480	447.035
500	465.661
512	476.837
750	698.492
960	894.07
1,000	931.323
1,024	953.674
2,000	1,862.65
2,048	1,907.35
3,000	2,793.97
4,000	3,725.29
5,000	4,656.61
6,000	5,587.94
8,000	7,450.58

How many gibibytes in gigabytes?

1 GB = 0.931323 GiB. There are 0.931323 gibibytes in 1 gigabytes.

100 GB = 93.1323 GiB. There are 93.1323 gibibytes in 100 gigabytes.

500 GB = 465.661 GiB. There are 465.661 gibibytes in 500 gigabytes.

1,000 GB = 931.323 GiB. There are 931.323 gibibytes in 1,000 gigabytes.

2,000 GB = 1,862.65 GiB. There are 1,862.65 gibibytes in 2,000 gigabytes.

gibibytes to gigabytes formula

GB = GiB × 2³⁰ ÷ 10⁹

1 gibibyte = 1.073741824 gigabytes, so multiply gibibytes by 1.073741824, or divide by 0.9313225746.

gibibytes to gigabytes table

gibibytes (GiB)	gigabytes (GB)
1	1.07374
2	2.14748
4	4.29497
8	8.58993
16	17.1799
32	34.3597
50	53.6871
64	68.7195
100	107.374
119	127.775
128	137.439
200	214.748
232	249.108
238	255.551
256	274.878
465	499.29
476	511.101
500	536.871
512	549.756
894	959.925
931	999.654
1,000	1,073.74
1,024	1,099.51
1,863	2,000.38
2,048	2,199.02
3,725	3,999.69
4,096	4,398.05
7,450	7,999.38

How many gigabytes in gibibytes?

1 GiB = 1.07374 GB. There are 1.07374 gigabytes in 1 gibibytes.

8 GiB = 8.58993 GB. There are 8.58993 gigabytes in 8 gibibytes.

100 GiB = 107.374 GB. There are 107.374 gigabytes in 100 gibibytes.

931 GiB = 999.654 GB. There are 999.654 gigabytes in 931 gibibytes.

1,024 GiB = 1,099.51 GB. There are 1,099.51 gigabytes in 1,024 gibibytes.

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How the GB To GiB works

This converts GB to GiB, and GiB back to GB. Type a size in gigabytes and get gibibytes as you type. A gigabyte is a billion bytes; a gibibyte is 1,073,741,824 bytes, 2³⁰. The gibibyte is 7.4% bigger, so the number goes down. This is the conversion behind every "my drive is smaller than the box says" question, and the table has the common drive sizes in it. Press the swap button to go the other way.

The formula. GiB = GB × 1,000,000,000 ÷ 1,073,741,824 = GB × 0.931323; GB = GiB × 1.073742. That is how many gibibytes an operating system reports for a drive sold in gigabytes.

Why a 1 TB drive shows as 931 GB

The drive holds 1,000,000,000,000 bytes, as the label says. Windows divides by 2³⁰ to get gigabytes, because it uses the binary convention, and 10¹² ÷ 1,073,741,824 = 931.32. It then prints "931 GB" when it should print "931 GiB". Nothing is missing and nothing has been lost to formatting; the drive maker and Windows are using different units with the same name. macOS, since 2009, divides by 10⁹ and shows 1 TB.

The factor

1 GB = 10⁹ bytes. 1 GiB = 2³⁰ = 1,073,741,824 bytes. So 1 GB = 10⁹ ÷ 2³⁰ = 0.931322574615 GiB. At each level the gap grows: kB to KiB is 2.4%, MB to MiB 4.9%, GB to GiB 7.4%, TB to TiB 10%. The IEC introduced the binary names in 1998; Windows, and most people, have not adopted them.

Worked example: a 500 GB SSD

500 × 0.9313 = 465.7 GiB. Windows shows "465 GB". A 250 GB drive shows 232 GiB, a 2 TB drive 1,862 GiB, a 4 TB drive 3,725 GiB. Some SSDs are sold as 480 GB or 960 GB rather than 512 or 1,024 because the controller reserves part of the flash for wear levelling; a "960 GB" drive is 894 GiB.

Worked example: a 64 GB phone

64 × 0.9313 = 59.6 GiB. The phone's settings screen may show either, and the operating system and preinstalled apps take 8–12 GB on top, which is why a 64 GB phone has about 50 GB free out of the box. A 128 GB phone is 119.2 GiB; 256 GB is 238.4 GiB.

Where the units actually apply

RAM is binary because memory is addressed in powers of two: an 8 GB module really is 8 GiB. Storage is decimal because there is no such constraint and a bigger number sells. Networks are decimal, in bits. Cloud storage plans are decimal. Windows is binary throughout, Linux mostly binary with correct labels, macOS decimal.

Rule of thumb

Take off 7%: 1,000 GB is about 930 GiB. For terabytes, take off 10%: a 1 TB drive is 0.91 TiB, and a 1 TB drive in gibibytes is 931 GiB.

Worked example: Windows says 931 GB

931.32 × 1.0737 = 1,000 GB, 1 TB. Windows measures in gibibytes and labels them GB, so a drive that Explorer reports as 931 GB is the 1 TB drive on the receipt. Likewise 465 GB is a 500 GB drive, 1,863 GB is 2 TB, 3,725 GB is 4 TB and 232 GB is 250 GB. The drive is exactly the size advertised; the units differ.

Worked example: 16 GiB of RAM

16 × 1.0737 = 17.18 GB. Memory is built in powers of two, so a 16 GB module holds 16 GiB, 17,179,869,184 bytes. This is the one place where the marketing number is the binary one. It is also why a cloud provider's "16 GB" virtual machine may show 15.6 GiB inside the VM after the hypervisor takes its share, or 16 GiB if the provider means binary.

GB to GiB conversion table

Gigabytes to gibibytes for common drive and file sizes

GB	GiB
1 GB	0.93 GiB
2 GB	1.86 GiB
4 GB	3.73 GiB
8 GB	7.45 GiB
16 GB	14.90 GiB
32 GB	29.80 GiB
64 GB	59.60 GiB
100 GB	93.13 GiB
120 GB	111.76 GiB
128 GB	119.21 GiB
240 GB	223.52 GiB
250 GB	232.83 GiB
256 GB	238.42 GiB
480 GB	447.03 GiB
500 GB	465.66 GiB
512 GB	476.84 GiB
1,000 GB	931.32 GiB
2,000 GB	1,862.65 GiB
4,000 GB	3,725.29 GiB
8,000 GB	7,450.58 GiB
10,000 GB	9,313.23 GiB
12,000 GB	11,175.87 GiB
16,000 GB	14,901.16 GiB
20,000 GB	18,626.45 GiB

FAQ

Why does my 1 TB drive only show 931 GB?

The drive holds a trillion bytes. Windows reports size in gibibytes (2³⁰ bytes) but labels them GB, and a trillion bytes is 931.32 GiB. The drive is not smaller than advertised; the units differ. macOS shows the same drive as 1 TB.

How many GiB is 1 GB?

0.9313 GiB. A gigabyte is 1,000,000,000 bytes and a gibibyte is 1,073,741,824, so the gibibyte is 7.4% larger and the count goes down. 100 GB is 93.1 GiB; 500 GB is 465.7 GiB.

Is GiB the same as GB?

No. GB is decimal, 10⁹ bytes; GiB is binary, 2³⁰ bytes. Windows uses the binary unit but writes GB, which is the source of the confusion. Linux, macOS and most modern software distinguish them.

Why is RAM 8 GB but a drive 8 GB is less?

RAM is made and addressed in powers of two, so "8 GB" of RAM is 8 GiB, 8,589,934,592 bytes, and Windows shows 8 GB. A drive sold as 8 GB is 8,000,000,000 bytes, 7.45 GiB, and Windows shows 7.45 GB.

How many GB is 1 GiB?

1.0737 GB, exactly 1.073741824. A gibibyte is 1,073,741,824 bytes and a gigabyte is a billion. So the gigabyte count is always 7.4% higher than the gibibyte count for the same data.