Capacitor Code Calculator
Enter the marking
Type the code printed on the top of the capacitor.
Examples — 104 (3-digit), 472K (with tolerance), 4R7 (R-decimal). Codes are interpreted in pF; J=±5%, K=±10%, M=±20%.
Decoded value
How to use this calculator
Type the characters printed on the capacitor. A 3- or 4-digit code works like an SMD resistor: the leading digits are the significant figures and the final digit is the power-of-ten multiplier, with the value expressed in picofarads — so 104 is 10 × 10⁴ = 100 000 pF = 0.1 µF. A trailing tolerance letter (J, K or M) gives the allowed deviation, and an R-decimal code such as 4R7 uses the letter R as a decimal point (4.7 pF). The decoded value and its pF/nF/µF equivalents update as you type.
What the value means in a circuit
Capacitance measures how much charge a component stores per volt (Q = C·V). That stored energy is what lets a capacitor smooth supplies, block DC while passing AC (coupling), set filter cutoffs together with a resistor, and time delays in RC circuits. Reading the code correctly is essential when substituting parts or building a BOM — a misread multiplier turns a 0.1 µF filter capacitor into a 100 µF one and can completely change a circuit's behaviour.