Capacitor Code Calculator

Small capacitors are too tiny to print a full value on, so manufacturers stamp them with a short code instead, and this calculator decodes that code into a capacitance you can actually use, shown in picofarads, nanofarads and microfarads at once. The most common marking is a three-digit code such as 104 or 223. It works just like the resistor colour code: the first two digits are the significant figures and the third digit tells you how many zeros to add, giving the value in picofarads. So 104 is 10 followed by four zeros, which is 100,000 pF, or 100 nF, or 0.1 uF, the same part written three different ways. Smaller capacitors often just print the value directly, so a code of 22 simply means 22 pF, and many parts add a tolerance letter such as J, K or M after the number, telling you how far the real value may stray from the nominal one. Enter the code, choose a tolerance letter if there is one, and the calculator returns the capacitance in all three units along with the tolerance, taking the guesswork and mental arithmetic out of reading a part. That is genuinely useful when you are sorting a parts drawer, following a circuit diagram, repairing electronics, or building a project from a kit, where matching the right capacitor matters and the codes are easy to misread. It is also a handy learning aid for electronics and physics students getting to grips with component markings and the picofarad, nanofarad and microfarad scale. The code system and a worked example are explained clearly below, so you can soon read most capacitors at a glance.

Calculate.co.nz is proud to be partnered with Health Based Building, a leader in sustainable and health-conscious building innovation. With over a century of experience, they develop high-performance systems like Foreverbreathe Specification, Magnum Board, and Foreverbreathe Paints to support energy-efficient, non-toxic living environments. Their commitment to healthier homes aligns with our belief that informed choices lead to better outcomes for Kiwi households.