Data storage converter guide
Data quantities use both decimal and binary systems. Decimal SI prefixes advance by powers of 1000: 1 kB = 1000 B and 1 GB = 1,000,000,000 B. IEC binary prefixes advance by powers of 1024: 1 KiB = 1024 B and 1 GiB = 1,073,741,824 B.
A byte contains 8 bits. Symbols are case-sensitive and distinct: bit is written bit, byte is B, kilobyte is kB, and kibibyte is KiB. The converter keeps these systems separate instead of treating MB and MiB as synonyms.
How to convert data storage units
- Enter the amount: Provide a finite, non-negative data quantity.
- Choose the source: Select the exact source symbol, paying attention to bit versus byte and decimal versus binary.
- Choose the target: Select the unit you want to receive, or use Swap to reverse the unit pair.
- Convert: Select Convert data storage to calculate using the defined unit factors.
Formula and variables
Every unit is converted to bits as a common base, then divided by the number of bits in the target unit.
target value = source value x (source bits per unit) / (target bits per unit)- bit — Bit
- Base binary information unit used by the converter.
- B — Byte
- Exactly 8 bits.
- k, M, G, T, P — SI prefixes
- Decimal powers of 1000.
- Ki, Mi, Gi, Ti, Pi — IEC prefixes
- Binary powers of 1024.
Convert a decimal gigabyte to gibibytes
Express 1 GB, defined as one billion bytes, in GiB.
- Amount
- 1
- From
- GB
- To
- GiB
- 1 GB = 1,000,000,000 B
- 1 GiB = 1,073,741,824 B
- 1,000,000,000 / 1,073,741,824
Result: 1 GB is approximately 0.9313225746 GiB.
The numeric value is smaller in GiB because each GiB contains more bytes than each GB.
Understanding your results
Decimal units
Use kB, MB, GB, TB, and PB for exact powers of 1000 bytes. These are common in storage-device capacity.
Binary units
Use KiB, MiB, GiB, TiB, and PiB for exact powers of 1024 bytes. These remove the ambiguity of using SI names for binary quantities.
Assumptions
- One byte equals exactly 8 bits.
- SI prefixes use powers of 1000 and IEC binary prefixes use powers of 1024.
- The entered amount is a non-negative finite scalar.
- The conversion describes quantity, not transfer time, encoding overhead, filesystem allocation, or usable capacity.
Limitations
- The calculator does not estimate formatted disk capacity, redundancy, compression, filesystem overhead, or network protocol overhead.
- Very large floating-point values can lose integer precision.
- Transfer-rate units per second are not included.
- Legacy ambiguous uses of KB to mean 1024 bytes must be identified before conversion.
Common mistakes
- Treating bit and byte as interchangeable.
- Using MB and MiB as if they were equal.
- Ignoring capitalization in symbols.
- Expecting advertised device capacity to equal formatted usable capacity.
- Converting a data quantity when a transfer rate or duration is actually needed.
Practical use cases
Storage capacity
Compare decimal manufacturer specifications with binary operating-system displays.
Data and networking
Convert between bit-based and byte-based quantities while retaining explicit unit definitions.
Planning and decision guide
Record the unit convention
Do not write an unlabeled number. Preserve the exact symbol and state whether a legacy source used an ambiguous prefix so that another person can reproduce the conversion.
Frequently asked questions
How many bits are in a byte?
One byte contains exactly 8 bits.
Are GB and GiB the same?
No. 1 GB is 10^9 bytes, while 1 GiB is 2^30 bytes.
What is the difference between MB and MiB?
1 MB is 1,000,000 bytes; 1 MiB is 1,048,576 bytes.
Why does a drive appear smaller in some software?
One cause is displaying decimal capacity in binary-sized units; formatting and system overhead can also reduce usable space.
Can this convert internet speed?
It converts quantities, not per-second rates. The bit/byte ratio still applies, but a rate calculator must preserve the time unit.
Sources and review
- Definitions of the SI units: The binary prefixes — National Institute of Standards and Technology. Accessed 2026-08-29.
- NIST Guide to the SI, Chapter 4 — National Institute of Standards and Technology. Accessed 2026-08-29.
Reviewed 2026-08-29.