How to Convert GB to GIB
1 GB (gigabyte) = 1,000,000,000 bytes. 1 GiB (gibibyte) = 1,073,741,824 bytes. To convert GB to GiB, multiply by 0.9313 (or exactly 1000/1024). At 100 GB: 93.13 GiB. At 1000 GB: 931.3 GiB. The same binary vs decimal gap applies at smaller scale, so the MB to MiB converter handles megabyte comparisons.
Example: 100 GB × 0.9313 = 93.13 GiB
Conversion Table
| GB |
GIB |
| 1 gb | 0.9313 gib |
| 2 gb | 1.8626 gib |
| 5 gb | 4.6565 gib |
| 10 gb | 9.313 gib |
| 20 gb | 18.626 gib |
| 50 gb | 46.565 gib |
| 100 gb | 93.13 gib |
| 250 gb | 232.825 gib |
| 500 gb | 465.65 gib |
| 1000 gb | 931.3 gib |
GB versus GiB: the 7 percent that confuses everyone
The confusion exists because two completely different definitions share the same two letters. A gigabyte (GB) as defined by drive manufacturers and the SI standard is exactly 1,000,000,000 bytes. A gibibyte (GiB) as defined by the IEC binary standard is exactly 1,073,741,824 bytes, which is 2 raised to the power of 30. The ratio between them is 1,073,741,824 divided by 1,000,000,000, which works out to about 1.074. So every GB on a drive label maps to only 0.9313 GiB in your file manager, a shortfall of about 6.9 percent (equivalently, a GiB is about 7.4 percent larger than a GB).
When you'll notice this: unpacking a new hard drive or SSD is the most common moment. A 1 TB drive (1,000 GB) shows up as 931 GiB in Windows or Linux. A 256 GB SSD in a laptop appears as about 238 GiB in Disk Management. The OS is not rounding, hiding recovery partitions, or doing anything unusual. It is simply using a binary count while the label used a decimal one. Partition overhead and recovery volumes do reduce capacity further, but the bulk of the difference between box and file manager is always this unit gap.
Cloud storage and network shares add a second layer of confusion. Many cloud providers (Google Drive, Dropbox, AWS S3) invoice in decimal gigabytes, the same convention as the drive box. But sync clients and backup tools often report progress in binary gibibytes. A completed 200 GB upload shows as 186 GiB in the client. The data transferred is identical; only the measuring stick changed. Comparing a cloud invoice to a sync-client summary without accounting for this almost always produces a spurious "missing" 7 to 8 percent.
Common mistakes to avoid: treating GB and GiB as interchangeable in storage planning formulas is the biggest one. If a server spec says it needs 500 GiB of usable space, ordering a 500 GB drive will leave you about 34 GiB short after the binary conversion. Order 540 GB or larger to arrive safely above 500 GiB. A second mistake is assuming the problem is drive failure or hidden partitions when disk utilities report less than the label. Run this converter first: if the result matches what your OS shows, the hardware is fine and the unit labeling is the entire explanation.
Frequently Asked Questions
My NAS shows 3.6 TiB available but I bought a 4 TB drive. Where did the space go?
Nothing is missing. Drive manufacturers count in decimal terabytes (1 TB = 1,000,000,000,000 bytes). File systems and OS tools report in binary tebibytes (1 TiB = 1,099,511,627,776 bytes). A 4 TB drive contains exactly 3.637 TiB of usable space. File system overhead and partition tables reduce it a little further, which is why NAS tools typically show 3.6 TiB for a 4 TB drive.
Does the GB vs GiB difference matter for cloud storage billing?
Yes. Cloud providers bill in decimal gigabytes. Backup software often reports in binary gibibytes. A 500 GB backup job (decimal) is about 466 GiB. If your backup tool shows 466 GiB completed and the cloud bill shows 500 GB used, both numbers are correct: they measure the same data in different units. Always confirm which convention your backup or storage software uses before comparing invoices to software reports.
I need 500 GiB of usable space for a virtual machine. What size drive should I order?
Order at least a 540 GB drive. A 500 GB drive yields only about 465 GiB once the binary conversion is applied, leaving you 35 GiB short before any partition table or file system overhead is counted. Divide your GiB requirement by 0.9313 to get the minimum GB size to order: 500 divided by 0.9313 is roughly 537 GB, so 540 GB is the practical safe minimum for commodity drives. For server storage where every gigabyte matters, round up to 600 GB to leave margin for formatting overhead.