How bits, decimal bytes and binary bytes convert exactly
Decimal gigabytes and binary gibibytes count different numbers of bytes. This tool keeps the letter case and IEC binary names visible, converting every selected amount through exact bytes rather than calling both units 'GB'.
A decimal GB and a binary GiB are close in name but not size. One GB is exactly one billion bytes; one GiB is 2³⁰ = 1,073,741,824 bytes. Converting a drive label or a file-size display without checking which convention each side uses can create an apparent capacity discrepancy. The converter keeps these names and symbols separate in its unit choices.
The byte bridge and decimal/binary family labels explain why GB and GiB differ; bit and byte symbols remain distinct so an eightfold mix-up is visible.
How the amount, bit or byte symbol and unit family set the result
Every conversion passes through an exact byte count. The choices that change the answer are the letter case of the symbol and whether a prefix steps by 1,000 or 1,024.
- Amount to convert
- Any nonnegative amount up to one trillion in the selected unit; fractions such as 1.5 GB are accepted. The result scales directly, so the one-unit factor in the facts can be reused for any other amount in the same pair. The list has no megabit or gigabit option, so enter those figures as plain bits.
- Bit (b) or byte (B)
- Only letter case separates these, and a byte is eight bits, so 8,000 b is exactly 1 kB. Selecting B for a figure stated in bits makes the answer eight times too large. Network speeds and some chip capacities are quoted in bits, while file sizes are almost always in bytes.
- Decimal family (kB, MB, GB, TB)
- These step by 1,000, as drive makers and SI prefixes define them. A drive sold as 1 TB holds 1,000,000,000,000 bytes, which is 931.322574615479 GiB or 0.909494701773 TiB. The difference is notation, not missing space.
- Binary family (KiB, MiB, GiB, TiB)
- These step by 1,024, so 1 KiB is 1.024 kB and the gap widens at each prefix, to about 7.4% at GiB and 10% at TiB. Some operating systems show binary amounts with labels such as GB, so choose GiB when a figure came from such a display.
- Display precision
- Results show up to twelve decimal places, and a nonzero result too small for that switches to scientific notation: one bit is 1.136868e-13 TiB. The amount in bytes listed in the facts is rounded to six decimal places.
Steps
- Enter a nonnegative bit or byte amount.
- Choose the exact source symbol, paying attention to lowercase b for bit and uppercase B for byte.
- Choose a decimal or binary destination and inspect the byte basis and one-unit factor.
Reading tip: The comparison tiles state the source family and destination family around the exact byte bridge. Look for lowercase b versus uppercase B before interpreting a transfer-rate or storage figure.
Storage and transfer figures where unit families get mixed
Compare a disk label
Translate decimal gigabytes into binary gibibytes without treating their byte sizes as equal.
Read memory figures
Check the exact binary size behind a reported MiB or GiB quantity.
Distinguish b from B
Convert a bit count to bytes while avoiding the common eightfold symbol confusion.
Verify a file estimate
Use the source-to-target factor to re-express one stated data amount in another unit.
How the calculation works
- B / b
- Uppercase byte / lowercase bit; one byte equals eight bits here.
- GB
- Decimal gigabyte, defined here as exactly one billion bytes.
- GiB
- Binary gibibyte, defined here as exactly 1,073,741,824 bytes.
- byte basis
- Common exact data quantity before division by the destination unit's size.
A formatted drive can report less usable capacity for reasons beyond decimal-versus-binary unit notation.
What every part means
- B / b
- Uppercase byte / lowercase bit; one byte equals eight bits here.
- GB
- Decimal gigabyte, defined here as exactly one billion bytes.
- GiB
- Binary gibibyte, defined here as exactly 1,073,741,824 bytes.
- byte basis
- Common exact data quantity before division by the destination unit's size.
Calculate it step by step
For bits, the bytes-per-bit factor is 1/8; one binary GiB uses 2³⁰ bytes.
A decimal GB uses 10⁹ bytes, not 2³⁰.
Use the displayed factor for another amount in the same source and destination units.
The factors are exact decimal strings for powers of ten or exact integer powers of two. Decimal arithmetic avoids a floating-point change to large byte totals; visible results are rounded only after division.
See how Calculation Guide tests examples and handles calculation limits.
See it in practice
- Amount to convert
- 1
- From data unit
- Gibibytes (GiB)
- To data unit
- Gigabytes (GB)
One GiB contains 1,073,741,824 B. Divide by 1,000,000,000 B per GB to obtain 1.073741824 GB; no bytes have been added.
- Amount in bytes1,073,741,824
- One-source-unit factor1 GiB = 1.073741824 GB
Interpretation & limitations
How to read your result
One GiB becomes 1.073741824 GB. This does not create data: the byte count is unchanged. A numerical amount grows when the destination unit contains fewer bytes.
Where this estimate stops
Actual file allocation and device usable capacity depend on filesystem overhead, reserved space, compression and manufacturer reporting. A network 'Mb' transfer rate also involves time and is not a stored byte amount.
Frequently asked questions
01Why is 1 GiB greater than 1 GB?
A GiB is 2³⁰ or 1,073,741,824 bytes, while a decimal GB is 10⁹ or 1,000,000,000 bytes.
02Is b the same as B?
No. Lowercase b is a bit; uppercase B is a byte. One byte is eight bits in this tool.
03Is one kB 1,024 bytes?
No in this converter. kB is decimal 1,000 bytes; KiB is binary 1,024 bytes.
04Why are bits and bytes separate choices?
They differ by eight to one, and their symbols differ only by letter case. Treating b as B would cause an eightfold error.
05Can the result be very small?
Yes. The display switches to scientific notation when a nonzero converted value would otherwise round to zero.
06Does the tool explain disk space shown by an operating system?
It explains unit differences. Filesystem formatting and reserved system space can create additional differences outside the conversion.
07Is a 100 Mbps connection 100 megabytes per second?
No. Mbps counts megabits each second. Entering 100,000,000 bits converts to 12.5 MB, so a 100 Mbps link moves at most about 12.5 MB of data per second, before protocol overhead and network conditions reduce it. This page converts the amount only; it does not model time or throughput.