Capacitor Codes

Large capacitor have the value printed plainly on them, but smaller ones often have just numbers printed.

The first two numbers are the 1st and 2nd significant digits and the third is a multiplier code.

If there are only two numbers, these are read as Pico-Farads. An example: 47 printed on a small disk can be assumed to be 47 Pico-Farads.

The third digit tells how many zeros to write after the first two digits.

 Digit Multipliers third digit multiplier (first two digits give the value in Pico-Farads) 0 1 1 10 2 100 3 1,000 4 10,000 5 100,000 6 not used 7 not used 8 .01 9 .1

Example: A capacitor marked '124' is 12 with 4 more zeros or 120,000pF which is otherwise referred to as a .12 uF capacitor.

There is sometimes a tolerance code given by a single letter. Example: a 103J is a 10,000 pF with +/-5% tolerance.

 Tolerance Code letter tolerance of capacitor B +/- 0.10% C +/- 0.25% D +/- 0.5% E +/- 0.5% F +/- 1% G +/- 2% H +/- 3% J +/- 5% K +/- 10% M +/- 20% N +/- 0.05% P +100% ,-0% Z +80%, -20%

There is also a 'letter-number-letter' code. For example, a labelled '224 Z5U' would represent a 220,000 pF capacitor with a low temperature rating of -10 deg C, a high temperature rating of +85 Deg C and a tolerance of +22%,-56%.

 Dielectric Codes First Letter Low Temperature Requirement Second Number High Temperature Requirement Third Letter Max Capacitance Change over Temperature Z +10 deg. C 2 +45 deg. C A +1.0% Y -30 deg. C 4 +65 deg. C B +/- 1.5% X -55 deg. C 5 +85 deg. C C +/- 2.2% 6 +105 deg. C D +/- 3.3% 7 +125 deg. C E +/- 4.7% F +/- 7.5% P +/- 10.0% R +/- 15.0% S +/- 22.0% T +22%, -33% U +22%, -56% V +22%, -82%