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Decimal to BCD Converter

Convert standard base-10 decimal numbers into 8421 Binary-Coded Decimal (BCD) 4-bit nibbles. Designed for software developers, electrical engineers, students, and computer architecture researchers requiring deterministic client-side accuracy.

Engine: Client-Side Verified (0ms Latency)

Enter any non-negative base 10 integer.

Calculated Output

Primary Representation
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Step-by-Step Mathematical Proof

Active Derivation
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Concept

What Is Decimal to BCD Converter?

Decimal to BCD conversion transforms standard decimal integers into Binary-Coded Decimal (8421 BCD). Rather than converting the entire number into a single binary integer, BCD independently translates each decimal digit (0 through 9) into its own 4-bit binary sequence (0000 to 1001).

Methodology

How Does It Work?

Split the decimal number into its individual digits. Replace each decimal digit with its corresponding 4-bit binary representation: 0=0000, 1=0001, 2=0010, 3=0011, 4=0100, 5=0101, 6=0110, 7=0111, 8=1000, 9=1001.

Formula & Rules

Mathematical Algorithm

N = \sum_{i=0}^{m-1} d_i 10^i \xrightarrow{} [\text{bin}_4(d_{m-1}) \dots \text{bin}_4(d_0)]
Worked Problem

Step-by-Step Example

Convert decimal 749 to BCD: Digit 7 -> 0111_2 Digit 4 -> 0100_2 Digit 9 -> 1001_2 BCD Result: 0111 0100 1001.

Important Rules & Edge Cases

  • Each decimal digit must be padded to exactly 4 bits.
  • Only decimal digits 0 through 9 are allowed.
  • Nibbles from 1010 to 1111 (10 to 15) are strictly illegal in BCD.

Practical Applications in Engineering

  • Digital electronic clocks, timers, and multimeters using 7-segment LED/LCD display drivers.
  • Financial software engines to avoid binary floating-point roundoff issues.
  • Point-of-sale (POS) terminal displays and cash register firmware.

Common Mistakes to Avoid

  • Caution: Converting the whole number into pure binary instead of encoding digit by digit (e.g. converting 12 into 1100 instead of 0001 0010).
  • Caution: Forgetting leading zeros on individual nibbles (e.g. writing 1 as 1 instead of 0001).
FAQ

Frequently Asked Questions

What is the difference between pure binary and BCD?

In pure binary, the entire number is converted into base 2 as a single positional value (e.g. 15 is 1111). In BCD, each decimal digit is converted into its own 4-bit nibble (e.g. 15 is 0001 0101).