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How to use
Convert bits, bytes, decimal SI units such as KB, MB and GB, and binary IEC units such as KiB, MiB and GiB. Rather than hiding the 1000-versus-1024 choice behind an ambiguous toggle, the unit names themselves make the standard explicit.
- Enter the data size.
- Choose the source unit, including explicit decimal or binary units.
- Choose the target unit and calculate to see the result and useful equivalents.
How it is calculated
Example
Example: 1 decimal GB is 1,000,000,000 bytes, which is about 0.9313225746 GiB. Conversely, 1 GiB is 1,073,741,824 bytes, or about 1.073741824 GB.
Important notes
KB, MB, GB, TB and PB are decimal powers of 1000 here; KiB, MiB, GiB, TiB and PiB are IEC binary powers of 1024. One byte is eight bits. Some operating systems historically calculate in binary while displaying a decimal-looking label, which can make device readouts confusing.
Worked examples and interpreting results
A decimal gigabyte is one billion bytes; a binary gibibyte is 1073741824 bytes. GB and GiB describe different scales despite their similar names.
| Case | Calculation | Result |
|---|---|---|
| Decimal gigabyte to bytes | 1 GB = 1000³ B | 1,000,000,000 B |
| Binary gibibyte to bytes | 1 GiB = 1024³ B | 1,073,741,824 B |
How to check the result
One byte contains eight bits. Distinguish B for bytes from b for bits, and decimal from binary multiples. Unit conversion does not calculate available space after system files or formatting.
Frequently asked questions
Does 1 GB equal 1024 MB?
Not under the SI definition used here: 1 GB = 1000 MB. In IEC units, 1 GiB = 1024 MiB.
Why can a 1 TB drive look smaller?
Manufacturers commonly advertise decimal bytes while software may divide by powers of 1024, producing a smaller numerical figure in binary units.
What is the difference between a bit and a byte?
One byte equals eight bits; they are different units.