Capacitor Code Calculator
Decode a ceramic capacitor's 3-digit code (like 104 → 100 nF) plus its tolerance letter, with a labelled cap visual and a full common-code reference.
100 nF
100000 pF · 100 nF · 0.1 µF · tolerance ±10%
Common codes
Reading the 3-digit code
Small ceramic capacitors are too tiny to print a value on, so they use the same trick as resistors: two significant digits and a multiplier — and the implied unit is always picofarads (pF).
For code 104: take 10, append 4 zeros → 100 000 pF = 100 nF = 0.1 µF. A code with a letter like 4R7 uses the R as a decimal point → 4.7 pF.
Tolerance letters
| Letter | Tolerance | Letter | Tolerance |
|---|---|---|---|
| B | ±0.1 pF | J | ±5% |
| C | ±0.25 pF | K | ±10% |
| D | ±0.5 pF | M | ±20% |
| F | ±1% | Z | +80% / −20% |
| G | ±2% | — | — |
Why pF, nF and µF all show up
The code is always picofarads, but datasheets, schematics and hobbyists each prefer a different scale: RF circuits talk in pF, decoupling caps in nF, and bulk/bypass in µF. 1 µF = 1000 nF = 1 000 000 pF, so this tool always shows all three to remove the guesswork.
Codes you will meet most
- 104 — 100 nF, the universal supply-decoupling cap next to almost every IC.
- 102 / 103 — 1 nF / 10 nF, common in filters and timing.
- 220 / 221 — 22 pF / 220 pF, typical crystal load and RF capacitors.
- 105 — 1 µF, often the largest ceramic before you move to electrolytics.