Enter a number and choose its base. You get the value in binary, octal, decimal, hex, and a custom base in one go. Handy for low-level code and number theory.
Enter a number to see the conversion steps.
Number systems use a fixed set of digits. The base (radix) is how many digits you have. Binary uses 0 and 1; decimal uses 0–9; hex uses 0–9 and A–F for 10–15.
Digits 0, 1. Used in computers and digital logic. Example: 1011₂ = 11₁₀.
Digits 0–7. Often used for Unix permissions. Example: 377₈ = 255₁₀.
Digits 0–9. Everyday numbers. Example: 255₁₀.
Digits 0–9, A–F. Common in programming and colors. Example: FF₁₆ = 255₁₀.
Multiply each digit by the base raised to its position, then add. Example: 1011₂ = 1×2³ + 0×2² + 1×2¹ + 1×2⁰ = 8 + 0 + 2 + 1 = 11₁₀.
Divide by the target base repeatedly. The remainders (read in reverse) give the digits. For non-decimal to non-decimal, convert via decimal first.
Some decimal fractions do not have a finite representation in other bases. The tool stops at the precision you set; the result may be repeating or approximate.
