What is BCD?
Binary-Coded Decimal stores each decimal digit as its own 4-bit binary number, using the weights 8-4-2-1. So 42 is 0100 0010 (4 then 2), not the plain binary 101010. BCD wastes some bits, because the codes 1010–1111 are never used, but it makes converting to and from human-readable digits trivial.
You'll find BCD in real-time clock chips, seven-segment display drivers, digital meters, financial hardware that must avoid binary rounding errors, and many electronics exam questions.
Frequently asked questions
What is 9 in BCD?
1001.
Is BCD the same as binary?
No. Binary converts the whole number, while BCD converts each digit separately.
How to use the Decimal to BCD Converter
- Paste the text, number or code.
- Choose encode/decode or the target format.
- Read the result instantly.
- Copy it into your code or terminal.
Why use this Decimal to BCD Converter
100% in your browser
Nothing you enter is uploaded or stored.
Instant results
Updates as you type, no waiting.
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Works on phones, tablets and desktops.
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Explained
Formulas, tables and sources on the page.
Decimal to BCD Converter: chart and reference data
Source: exact arithmetic
| Decimal | Binary | Hex | Gray code | BCD |
|---|---|---|---|---|
| 0 | 0000 | 0 | 0000 | 0000 0000 |
| 1 | 0001 | 1 | 0001 | 0000 0001 |
| 2 | 0010 | 2 | 0011 | 0000 0010 |
| 3 | 0011 | 3 | 0010 | 0000 0011 |
| 4 | 0100 | 4 | 0110 | 0000 0100 |
| 5 | 0101 | 5 | 0111 | 0000 0101 |
| 6 | 0110 | 6 | 0101 | 0000 0110 |
| 7 | 0111 | 7 | 0100 | 0000 0111 |
| 8 | 1000 | 8 | 1100 | 0000 1000 |
| 9 | 1001 | 9 | 1101 | 0000 1001 |
| 10 | 1010 | A | 1111 | 0001 0000 |
| 11 | 1011 | B | 1110 | 0001 0001 |
| 12 | 1100 | C | 1010 | 0001 0010 |
| 13 | 1101 | D | 1011 | 0001 0011 |
| 14 | 1110 | E | 1001 | 0001 0100 |
| 15 | 1111 | F | 1000 | 0001 0101 |
Decimal to BCD Converter compared with the alternatives
| Option | Setup | Privacy | Speed |
|---|---|---|---|
| This tool | None | Local | Instant |
| Command line (base64, xxd) | Terminal | Local | Instant |
| Random online converter | None | May log input | Varies |
Who uses it in the UK
- Debugging APIs, URLs and HTML
- Embedded and electronics work
- Computer Science GCSE and A-level
- Inspecting data and encodings
More questions
Is it safe to paste API keys or tokens here?
The conversion runs entirely in your browser, so nothing is sent anywhere. Still, treat secrets carefully and never share decoded tokens in screenshots.
Is encoding the same as encryption?
No. Base64, URL and HTML encoding are reversible by anyone. They make data safe to transport or display, not secret.
Which standard does it follow?
Base64 follows RFC 4648, URL percent-encoding follows RFC 3986 and text is handled as UTF-8, matching modern browsers and servers.
Does it handle large inputs?
Yes, up to what your browser memory allows – typically several megabytes of text without problems.
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