Reference Guide

Capacitor Code Chart: 104, 103 and Tolerance Codes

A 3-digit capacitor code is a value in picofarads: the first two digits are the number, the third is how many zeros follow. So 104 = 100,000 pF = 100 nF = 0.1 µF, and 103 = 10,000 pF = 10 nF = 0.01 µF. A trailing letter is tolerance — J is ±5%, K is ±10%, M is ±20%. The charts below decode any code both ways; to check a part you have identified, use our Capacitor Testing Guide.

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The 3-Digit Code Rule

104

Example Code: 104

1st Digit

First significant figure

2nd Digit

Second significant figure

Multiplier

Add 4 zeros (0000) to the end

Result: 100,000 pF

= 100 nF = 0.1 µF

Common Codes Reference Table

Code	pF (Pico)	nF (Nano)	µF (Micro)
101	100 pF	0.1 nF	0.0001 µF
102	1,000 pF	1 nF	0.001 µF
103	10,000 pF	10 nF	0.01 µF
104	100,000 pF	100 nF	0.1 µF
223	22,000 pF	22 nF	0.022 µF
224	220,000 pF	220 nF	0.22 µF
334	330,000 pF	330 nF	0.33 µF
473	47,000 pF	47 nF	0.047 µF
474	470,000 pF	470 nF	0.47 µF
105	1,000,000 pF	1,000 nF	1.0 µF

Tolerance Letter Codes

The letter after the numbers indicates how precise the capacitor is. "J" is very common (±5%).

± 1%

Tight tolerance

± 2%

Tight tolerance

± 5%

Moderate tolerance

± 10%

Common tolerance

± 20%

Broad tolerance

+80% / -20%

Asymmetric tolerance

Reverse Engineering Tip: A tolerance letter describes the permitted capacitance range, not the dielectric or quality. For example, 104J commonly means 0.1 µF ±5%; verify the voltage rating and capacitor type against the manufacturer's part number and datasheet.

Wait! Do you see "X2" or "Y2"?

If your capacitor has markings like X1, X2, Y1, or Y2 (often with many safety logos like UL, VDE), it is a Safety Capacitor designed for AC mains filtering.

DO NOT replace these with standard generic capacitors. You must replace them with the exact same Safety Class (e.g., replace an X2 with an X2) to maintain fire safety and shock protection compliance.

Voltage Rating Codes

Sometimes voltage is written directly (e.g., "50V"). Other parts use a manufacturer-specific code. The examples below apply only when the part's datasheet uses this scheme: a trailing "J" can mean ±5% capacitance tolerance, while "1J" is a separate 63V code here. Confirm the series, voltage rating, dielectric, and any required safety class before selecting a replacement.

Code	Voltage (DC)	Code	Voltage (DC)
0J	6.3V	2A	100V
1A	10V	2Q	110V
1C	16V	2B	125V
1E	25V	2E	250V
1V	35V	2G	400V
1H	50V	2J	630V
1J	63V	3A	1000V (1kV)

Capacitor Codes FAQ

What does 104 mean on a capacitor?

104 is a 3-digit code measured in picofarads (pF). The first two digits (10) are the significant figures. The third digit (4) is the number of zeros to add. So 104 = 10 followed by four zeros = 100,000 pF, which converts to 100 nF or 0.1 µF.

What does the letter J mean on a capacitor?

The letter indicates tolerance (precision). J = ±5%. If you buy a 100µF capacitor with a "J" code, the actual value will be between 95µF and 105µF. Common codes: J=±5%, K=±10%, M=±20%.

How do I read voltage codes like 2A?

In the voltage-code scheme shown here, 2A = 100V DC, 1H = 50V DC, and 2E = 250V DC. These codes are not universal: confirm the manufacturer and series datasheet before choosing a replacement. A trailing J after a capacitance code usually means ±5% tolerance, while 1J is a separate voltage code in this scheme. Match the required capacitor type and safety class as well as the voltage rating.

What is 100nK?

100n means 100 nanoFarads (which is 0.1µF). The "K" is the tolerance of ±10%. So "100nK" = 0.1µF ±10%.

What is the difference between µF, nF, and pF?

They are units of capacitance. 1 µF (micro) = 1,000 nF (nano) = 1,000,000 pF (pico). To convert pF to µF, move the decimal point 6 places to the left. 100,000pF = 0.1µF.

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