BCD to Decimal Converter
Convert Binary-Coded Decimal to decimal, live as you type.
Binary-Coded Decimal encodes each decimal digit as its own 4-bit binary group (0000-1001), unlike regular binary which encodes the whole number at once. Converts live as you type, entirely in your browser.
What is BCD to Decimal Converter?
Binary-Coded Decimal (BCD) encodes each decimal digit as its own 4-bit binary group, rather than encoding the whole number at once the way regular ("pure") binary does. It's still used in digital clocks, calculators, and older embedded/financial systems where preserving exact decimal digits — with no binary-to-decimal rounding — matters more than storage efficiency. Paste a BCD binary string (groups of 4 bits, space-separated) and get the decimal value instantly. Because each nibble represents exactly one digit 0-9, only the bit patterns 0000 through 1001 are valid; 1010 through 1111 have no BCD meaning and are flagged as invalid rather than silently converted. Conversion happens live as you type, entirely in your browser — nothing is sent to a server.
FAQ
BCD must be in groups of exactly 4 bits, and each group's value must be 0-9 (binary 0000-1001) — groups representing 10-15 (1010-1111) aren't valid BCD digits.
Regular binary encodes the whole number as one value, which is efficient but can introduce rounding when converting decimal fractions or displaying digit-by-digit (as on a seven-segment display). BCD keeps each decimal digit exact and independently addressable, at the cost of using more bits overall.
This page currently converts BCD to decimal only — for the reverse, split your decimal number into digits and write each one as its own 4-bit binary group (e.g. 9 → 1001).