BCD to Decimal Converter

Convert Binary-Coded Decimal (BCD) values to standard decimal numbers, or encode decimal numbers into BCD format. Essential for working with financial data, hardware registers, and embedded systems.

BCD to Decimal Converter

Convert Binary Coded Decimal (BCD) to decimal numbers and vice versa

Conversion Type

BCD Format:

BCD Binary

Decimal Result

About BCD

Binary Coded Decimal (BCD) is a class of binary encodings where each decimal digit is represented by a fixed number of bits, usually four or eight.

Packed BCD stores two decimal digits per byte (more space-efficient), while Unpacked BCD stores one digit per byte (simpler for processing). BCD is used in digital displays, calculators, and financial systems requiring exact decimal representation.

How the BCD to Decimal Converter Works

Enter BCD (Binary-Coded Decimal) in binary, hex, or decimal format. The converter automatically detects the input format and converts to standard decimal.

Each 4-bit nibble in BCD represents one decimal digit (0-9). The converter extracts each nibble and builds the decimal number. Invalid BCD values (A-F) are flagged.

Choose between packed BCD (two digits per byte) or unpacked (one digit per byte). The converter handles both formats. Results show the decimal value and breakdown of each digit.

When You'd Actually Use This

Reading RTC chip values

Real-time clock chips store time in BCD. Read the register values and convert to decimal for display. Essential for embedded projects.

Debugging digital instruments

Multimeters and counters often use BCD internally. Capture bus data and convert to see the actual readings. Understand instrument communication.

Processing calculator protocols

Vintage calculators used BCD for display. Reverse engineering calculator protocols requires BCD conversion. Understand how values are transmitted.

Working with PLC data

Programmable logic controllers often use BCD for numeric I/O. Convert BCD inputs to decimal for HMI display. Process thumbwheel switch inputs.

Analyzing financial data formats

Some financial systems store decimals in BCD. Avoid floating-point errors. Convert BCD to decimal for accurate calculations.

Interfacing with 7-segment displays

Display drivers expect BCD input. Convert decimal values to BCD for display. Read back BCD from display controllers.

What to Know Before Using

BCD only uses digits 0-9.Each nibble must be 0000-1001 (0-9). Values 1010-1111 (A-F) are invalid in BCD. Invalid values indicate wrong format or data corruption.

Packed vs unpacked matters.Packed: 0x25 = decimal 25. Unpacked: 0x02 0x05 = decimal 25. Same result, different storage. Know which format your system uses.

Leading zeros are significant.BCD 0000 0101 is 05, not 5. Leading zeros matter in some applications. Time values especially: 09:05 not 9:5.

Byte order affects multi-byte values.Multi-byte BCD may be big-endian or little-endian. 0x1234 could be 1234 or 3412. Know your system's byte order.

Pro tip: When reading BCD from hardware, always validate each nibble. If you see A-F, something's wrong. Could be wrong address, timing issue, or protocol mismatch.

Common Questions

How do I recognize BCD?

In hex dump, BCD looks like readable digits. 0x12345678 in BCD is decimal 12345678. In binary, each nibble is 0000-1001 only.

What's packed BCD?

Two decimal digits per byte. High nibble is tens, low nibble is ones. 0x59 = decimal 59. Most space-efficient BCD format.

What's unpacked BCD?

One digit per byte. High nibble is usually 0. 0x05 = decimal 5. Simpler for some hardware but uses twice the space.

Can BCD represent decimals?

Standard BCD is integers only. Some systems use implied decimal point. 0x1234 with 2 implied decimals = 12.34. The position isn't stored.

Why not just use binary?

BCD converts to decimal digits easily. No division needed. Hardware for displays works directly with BCD. Simpler for human-readable output.

How do I convert decimal to BCD?

Take each decimal digit, convert to 4-bit binary. 123 becomes 0001 0010 0011. Each digit independently encoded.

What's the BCD for time 12:34:56?

Hours: 0x12, Minutes: 0x34, Seconds: 0x56. Three bytes total. Each byte holds two decimal digits in packed BCD.

Other Free Tools

Search tools

BCD to Decimal Converter