Capacitor Code Calculator
Turn 3-digit ceramic capacitor codes like 104 into pF/nF/µF — with tolerance letters and voltage markings explained.
Capacitor Code Calculator computes the capacitance behind 3-digit ceramic capacitor codes — free, instant and private in your browser. Hobbyists sorting parts drawers and techs reading disc ceramics and film caps use it to skip the datasheet algebra: type your numbers, read the answer with the substituted formula shown step by step, and share an exact permalink of the calculation.
About Capacitor Code Calculator
Capacitor Code Calculator computes the capacitance behind 3-digit ceramic capacitor codes using the standard engineering relation: C(pF) = two digits × 10^(third digit); a trailing letter is tolerance (J ±5 %, K ±10 %, M ±20 %). Worked live: '104' is 10 × 10⁴ pF = 100 nF — the most common bypass cap on Earth. The result recalculates on every keystroke, the worked-example panel shows your numbers substituted into the formula, and the Copy permalink button encodes the inputs in the URL so a colleague opens exactly your calculation. Everything runs client-side — nothing you type leaves your device.
How to use Capacitor Code Calculator
- 1Enter your values — the tool starts with realistic defaults for this exact use case, so the worked example is meaningful immediately.
- 2Read the live result and the worked-example panel, which substitutes your numbers into the formula step by step.
- 3Adjust any input to compare scenarios, then use Copy result or Copy permalink to share the calculation.
Why use Capacitor Code Calculator?
- ✓Implements the real formula — C(pF) = two digits × 10^(third digit) — with the substitution shown, not a black box
- ✓Built for hobbyists sorting parts drawers and techs reading disc ceramics and film caps
- ✓Copy result and permalink buttons — share the exact calculation in a README, forum answer or design review
- ✓100% free, no sign-up, runs entirely in your browser (works offline once loaded)
Frequently asked questions
How do you calculate capacitor code?+
The capacitance behind 3-digit ceramic capacitor codes follows C(pF) = two digits × 10^(third digit); a trailing letter is tolerance (J ±5 %, K ±10 %, M ±20 %). For example, '104' is 10 × 10⁴ pF = 100 nF — the most common bypass cap on Earth. The calculator applies the same relation and shows the substituted arithmetic so you can verify every step.
Is '104' the same as 0.1 µF?+
Yes: 104 = 10 × 10⁴ pF = 100 000 pF = 100 nF = 0.1 µF. The pF/nF/µF ladder trips everyone once — divide by 1000 each step up.
Why doesn't the code tell me the voltage rating?+
Small ceramics usually omit it; the body size and dielectric class hint at it but only the datasheet or the reel label is definitive. When in doubt on mains or high-voltage rails, replace with a part of known rating — a 50 V disc across 230 V mains fails violently.
Is the Capacitor Code Calculator free and private?+
Yes — completely free with no sign-up or usage limits, and it runs entirely in your browser: the values you enter are never uploaded or stored on a server.
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