About this tool
Capacitor Code Calculator is a free, in-browser tool that decodes the printed marking on ceramic and film capacitors into a real capacitance, and converts a capacitance back into the nearest 3-digit code. Everything runs locally in your browser — nothing is uploaded.
A 3-digit code XYZ means capacitance = (10·X + Y) × 10^Z picofarads. For example 104 gives (10·1 + 0) × 10⁴ = 100000 pF = 100 nF = 0.1 µF. Codes of one or two digits are read directly as picofarads (a bare 22 is 22 pF). An optional trailing letter is the tolerance: J = ±5%, K = ±10%, M = ±20%, F = ±1%, G = ±2%, D = ±0.5%. In value-to-code mode the tool finds the two significant digits and the power-of-ten multiplier that best reproduce the value you enter.
Use it when you are reading a marking like "473K" off a board or picking a substitute part: type the code to see pF, nF and µF at a glance, or switch modes and enter a target capacitance to get the code to look for.