GiB to GB converter
Type a size in GiB to get gigabytes. 16 GiB is 17.18 GB. The menus cover KiB, MiB, GiB, TiB and their decimal partners in both directions, so you can also turn GB to GiB or TiB to TB.
Show the working
Same size in every unit
Conversion table
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GiB vs GB
A gigabyte (GB) is 1,000,000,000 bytes. A gibibyte (GiB) is 1,073,741,824 bytes, which is 1,024 × 1,024 × 1,024. So a GiB is about 7.4% bigger than a GB. The "bi" units were added by the IEC in 1998 so that people could tell the two apart, and NIST keeps a short summary of the official binary prefixes.

GiB to GB formula
- GB = GiB × 1.073741824
- GiB = GB ÷ 1.073741824, which is about GB × 0.931
- MB = MiB × 1.048576, and TB = TiB × 1.099511627776
Open "Show the working" to see the exact byte counts for the two units you picked. For other unit pairs, the byte converter has a 1000 or 1024 switch.
Why your drive looks smaller

Drive makers count in GB. Windows counts in GiB but still writes "GB" on the screen. So a drive sold as 1 TB shows about 931 GB, and a 500 GB drive shows about 465 GB. No space is missing. To convert drive sizes without mixing the two systems, use the TB to GB converter. macOS has used decimal GB since 2009, so a Mac shows the size printed on the box.
GiB to GB chart
| GiB | GB | GB | GiB |
|---|---|---|---|
| 1 | 1.074 | 1 | 0.931 |
| 4 | 4.295 | 64 | 59.605 |
| 8 | 8.590 | 128 | 119.209 |
| 16 | 17.180 | 256 | 238.419 |
| 32 | 34.360 | 500 | 465.661 |
| 64 | 68.719 | 1,000 | 931.323 |
MiB to MB and TiB to TB
The same idea works at every size, and the gap grows with each step: a MiB is 4.86% bigger than a MB and a TiB is 9.95% bigger than a TB. Pick MiB, TiB or KiB in the From menu. RAM is usually sold in binary units, so 16 GB of RAM is really 16 GiB. To break a size into megabytes within one system, use the GB to MB converter.
Frequently asked questions
Is a GiB the same as a GB?
No. A GiB is 1,073,741,824 bytes and a GB is 1,000,000,000 bytes, so 1 GiB is 1.074 GB.
How much GiB is 1 GB?
About 0.931 GiB.
How many GB is 16 GiB?
17.18 GB.
Which one does Windows use?
Windows measures in GiB but labels the result GB. Linux tools and macOS often use decimal GB, and many Linux tools write G for GiB.
How many GiB is a 1 TB drive?
About 931 GiB, which Windows shows as 931 GB.

