Ceramic Capacitor Code Converter (Code to Capacitance & Capacitance to Code)
Decode a 3-digit ceramic capacitor code like "104" into pF, nF, and µF instantly, or convert a capacitance back into the standard code. Includes a tolerance letter table.
Tolerance letter reference (EIA standard)
| Letter | Tolerance |
|---|---|
| B | ±0.1pF |
| C | ±0.25pF |
| D | ±0.5pF |
| F | ±1% |
| G | ±2% |
| J | ±5% |
| K | ±10% |
| M | ±20% |
| Z | +80% / -20% |
Tips
- The only exception is a third digit of "9", which means ×10^-1 (multiply by 0.1), not ×10^9. So "339" is 33 × 0.1 = 3.3pF.
- A 2-digit code like "47" has no multiplier at all — it's simply the pF value directly. This is common on very small ceramic capacitors under 10pF.
- The trailing letter is a tolerance code. General-purpose parts commonly use K (±10%) or M (±20%), while precision parts use J (±5%) or F (±1%).
- The "Capacitance to Code" mode always produces a standard 3-digit code. If your input doesn't fit cleanly into 2 significant figures, it gets rounded to the nearest representable value.
- If a marking like "104" is too worn or small to read clearly, measure the capacitance with a multimeter and cross-check it using the "Capacitance to Code" mode.
Frequently Asked Questions
Side Note — A Capacitor Code Is the Numeric Cousin of the Resistor Color Code
Most ceramic capacitors are tiny, and like resistors, there simply isn't room to print the full capacitance value in text. So the EIA (Electronic Industries Alliance) and JIS (Japanese Industrial Standards) standardized a compact 3-digit numeric code combining two significant digits with a single multiplier digit — a similar idea to the resistor color code, just expressed with numbers and a letter instead of colored bands. Both systems solve the same underlying problem: packing a lot of information onto a very small part.
The trickiest part of this 3-digit system is what happens when the multiplier digit is "9". Digits 0 through 8 are used directly as a power of ten, but 9 is a special case meaning ×10^-1 (0.1×) rather than ×10^9. Misreading "339" as 33 × 10^9 pF instead of the correct 3.3pF would be off by many orders of magnitude — a mistake that's common enough to be called out explicitly in many textbooks and datasheets as a classic beginner pitfall.
Capacitor code tables are a standard fixture in electronics hobbyist sites and datasheet appendices, often presented right alongside resistor color code charts. But actually keying in the code printed on a real part to check its value — or working the other direction from a desired capacitance to a standard code — is something a static reference table alone can't do. Paired with the resistor color code calculator in the same physics category, this tool rounds out the basic lookup work involved in reading passive components.