What is the 3-digit capacitor code system?
Ceramic capacitors are too small to print their full value, so a 3-digit code is used. The first two digits are the significant figures of the capacitance in picofarads, and the third digit is the power-of-10 multiplier. For example, '104' means 10 × 10⁴ = 100,000 pF = 100 nF = 0.1 µF. See also our calculate Battery Capacity Estimated Battery Life.
What does 'R' mean in a capacitor code?
'R' is used as a decimal point indicator in capacitor codes. For example, '3R3' means 3.3 pF and '1R5' means 1.5 pF. This notation is used when the value is less than 10 pF and a decimal place is needed.
How do I read a capacitor tolerance code?
Tolerance codes are single letters appended to the capacitor marking. Common codes include J (±5%), K (±10%), and M (±20%). Some codes like C (±0.25 pF) and D (±0.5 pF) are absolute tolerances used for very small capacitances rather than percentages.
What capacitor types use the 3-digit code?
The 3-digit code system is primarily used on ceramic (disc and MLCC), film, and SMD (surface mount) capacitors. Electrolytic and tantalum capacitors are typically large enough to print their full value directly, so they rarely use this coding system. You might also find our LED Resistor Calculator useful.
How do I convert a capacitor code to microfarads?
First decode the code to picofarads using the multiplier rule, then divide by 1,000,000 to get microfarads. For example, code '104' = 100,000 pF ÷ 1,000,000 = 0.1 µF. This calculator performs all unit conversions automatically.
What is the difference between pF, nF, and µF?
These are all units of capacitance. 1 microfarad (µF) = 1,000 nanofarads (nF) = 1,000,000 picofarads (pF). Small ceramic capacitors are often measured in pF or nF, while larger electrolytic capacitors are measured in µF.
How do I convert a known capacitance value back to a capacitor code?
Switch the calculator to 'Value → Code' mode, enter your capacitance value and select its unit (pF, nF, or µF). The calculator converts the value to picofarads, identifies the two significant digits and the appropriate power-of-10 multiplier, and outputs the corresponding 3-digit code.
What if the third digit of my capacitor code is 8 or 9?
A third digit of 8 means multiply by 0.01, and a digit of 9 means multiply by 0.1. These are special cases for very small capacitance values. For example, '338' = 33 × 0.01 = 0.33 pF, and '229' = 22 × 0.1 = 2.2 pF.