BCD to Decimal Converter

Convert Binary-Coded Decimal to decimal, live as you type.

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bcd-to-decimal-converteryour input stays here

BCD (binary)

Decimal

123

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.

Need the opposite? Decimal to Binary Converter

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.

Decimal Digit to BCD Nibble Chart

Decimal Digit	BCD (4-bit)
0	0000
1	0001
2	0010
3	0011
4	0100
5	0101
6	0110
7	0111
8	1000
9	1001

How to Use the BCD to Decimal Converter

1
Enter a BCD Bit String: Type a binary string in 4-bit groups, such as 0101 0010 1001.
2
Read the Decimal Result Instantly: The decoded decimal value appears automatically as you type, with invalid nibbles flagged.
3
Copy the Result: Use the copy button to copy the decimal value for use in code or documentation.

How BCD Encoding Works

Each decimal digit (0-9) gets its own fixed 4-bit binary group, called a nibble. Unlike regular binary, where the whole number is converted as a single value, BCD converts one digit at a time and keeps the groups side by side. A multi-digit number is just its digits' nibbles placed next to each other, in order.

How to Convert BCD to Decimal

Split the bit string into groups of 4, then convert each group to its decimal digit (0000-1001 map to 0-9) and read the digits in order. For example, 0100 0111 splits into 0100 (= 4) and 0111 (= 7), giving the decimal number 47, not 71, since the groups are read left to right in the order the digits appear.

Examples

OUTPUT

0101 0010 1001 → 5, 2, 9 → 529
0000 1001 → 0, 9 → 09 (a leading-zero digit is still a valid nibble)
0001 0000 0000 → 1, 0, 0 → 100

FAQs

Frequently Asked Questions

Common questions about BCD to Decimal Converter.

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).

BCD remains common in digital clocks, calculators, seven-segment displays, and some financial and embedded systems where exact decimal digit representation (no binary rounding of a fractional decimal value) is more important than storage efficiency.

Yes, Bytelify's BCD to Decimal Converter is free with no account or sign-up required.

No. The conversion runs entirely client-side in your browser, so nothing you paste is sent anywhere.

The BCD this tool decodes represents one digit per 4-bit nibble. "Packed BCD" is the same idea but stores two digits per 8-bit byte (one per nibble), which is a common storage optimization in older systems and mainframes.