BCD to Hex Converter
Convert a BCD (binary-coded decimal) value into hexadecimal — unpack each decimal digit and re-encode the number in true hex.
How to Convert BCD to Hex
A BCD value already reads as a plain decimal number — each nibble holds one digit, in order. Take that number at face value as decimal, then convert it to hex using the standard repeated-division-by-16 method.
BCD to Hex Example, Step by Step
123 (BCD) = 7B
123 in BCD = 0x7B
BCD nibbles: 1, 2, 3 Read directly as decimal: 123 123 decimal = 7B hex
| Step | Description | Result |
|---|---|---|
| Read the BCD nibbles | 1, 2, 3 | 3 digits |
| Interpret as decimal | reads directly as 123 | 123 |
| Convert to hex | 123 decimal = 7B hex | 7B |
Common Mistakes When Converting BCD to Hex
- Entering A-F as if they were valid BCD digits — BCD only uses 0-9.
- Treating the BCD input as if it were already hex, skipping the decimal-interpretation step.
- Forgetting leading zero nibbles are still significant digits in BCD.
Frequently Asked Questions
How do you convert BCD to hex?
Read the BCD nibbles as an ordinary decimal number (since that's what each nibble represents), then convert that decimal number to hex the normal way.
Why doesn't the BCD input accept letters A-F?
Because a valid BCD nibble only ever represents a decimal digit, 0-9 — A-F have no meaning in BCD, so a BCD value containing them is invalid by definition.
Where would I need to convert BCD to hex?
Reading raw output from a real-time clock (RTC) chip or BCD-based digital display and converting it into standard hex for use elsewhere in your code.
Is BCD to hex the reverse of hex to BCD?
Yes exactly — this page takes packed decimal digits and produces true hex; Hex to BCD does the opposite.
What's the largest BCD value this handles?
There's no fixed limit — the underlying engine uses arbitrary-precision arithmetic, so BCD values of any length convert correctly.
Does BCD to hex ever change the number of digits?
Often yes — hex is more compact per digit than BCD, so the hex result is frequently shorter than the original BCD value once converted.