Convert signed integers and fractions between bases 2-36 without losing large-number precision. Repeating and truncated fractions are labelled.
Up to 512 digits. Integers use exact arbitrary-precision math. Fractional outputs show exact, repeating, or truncated status.
This panel deliberately uses browser IEEE 754 Number/Float32 rounding. It is separate from the exact base converter.
A number base (or radix) determines the available digits and each digit's positional value. Decimal uses 0-9, binary uses 0-1, and hexadecimal uses 0-9 plus A-F. This converter supports signed values in bases 2-36. Integer conversion uses arbitrary-precision math, so values larger than JavaScript's safe-integer limit are not rounded.
0b or grouping separators.To convert by hand, multiply each digit by its base raised to the digit's position and sum them for the decimal value (for example binary 1011 = 1×2³ + 0×2² + 1×2¹ + 1×2⁰ = 11). To go from decimal to another base, divide repeatedly by the target base and read the remainders from bottom to top. Because each hex digit maps to exactly 4 binary bits and each octal digit to 3 bits, hex and octal are compact shorthands for binary.
The supporting panels have narrower contracts: IEEE 754 deliberately shows rounded browser Float32 and Float64 layouts; two's complement checks signed 8/16/32/64-bit ranges; bitwise operations use signed 32-bit semantics; and binary arithmetic accepts signed integers with exact large-number results. All calculations run locally in this browser tab and are not saved automatically.