Bits and bytes
A bit is a single binary digit, 0 or 1; eight bits make one byte. Network speeds (Mbit/s), audio bitrates and encryption key sizes are given in bits.
A byte is eight bits, enough to store one character of ASCII text. File sizes, memory and storage are all counted in bytes and their multiples.
Worked example
Convert 256 bit: 256 × 0.125 = 32, so 256 bits is 32 bytes. Likewise 100 bit = 12.5 B.
Estimating in your head
Divide by 8 for a quick figure; it is off by about 0%. For 256 bit that gives 32 B, against 32 exactly.
Going the other way
To convert bytes to bits, divide by 0.125 (or multiply by 8).
How this works
B = bit × 0.125
1 bit = 0.125 B and 1 B = 1 B, both by definition, so the factor is their ratio: 0.125 exactly. Results drop binary floating-point noise beyond 15 significant digits and display at the precision you choose (6 significant figures by default). Copy result copies the full value.
Frequently asked
How many bytes are in a bit?
1 bit = 0.125 bytes, exactly. The value follows from the unit definitions, so it never changes.
How do I convert bits to bytes?
Multiply by 0.125. For example, 100 bit × 0.125 = 12.5 B.
What is 1,000 bit in bytes?
1,000 bit = 125 B. The table next to the converter lists more common values.
Is the result rounded?
Only on screen. The page computes with the exact definitions and removes floating-point noise past 15 significant digits; pick 3 to 12 significant figures, or use Copy result for the full value.
Sources
- NIST — Prefixes for binary multiples (IEC 80000-13)
- BIPM — The International System of Units (SI Brochure), 9th edition
- Wikipedia — Byte
Reviewed Oct 17, 2026 · test vectors fixtures/units/data/bits-to-bytes/