Capacitor Code Calculator

How to read a capacitor code

The first two digits are the value, the third is the exponent, and the unit is the picofarad

Small capacitors have no room to print "0.1 µF", so they carry a 3-digit code: the first two digits are the significant digits and the third is the power of ten to multiply by, with the result in picofarads (pF). 104 is 10 × 10⁴ pF = 100,000 pF, which is 100 nF or 0.1 µF. It is not 104 pF, the most common mistake. A letter after the code gives the tolerance: J is ±5%, K is ±10% and M is ±20%; Z is −20% and +80%, and C and D (±0.25 pF and ±0.5 pF) are absolute tolerances, in pF, for small values. Below 10 pF the letter R acts as the decimal point (2R2 = 2.2 pF). There is also the RKM notation, where the prefix letter takes the place of the decimal point: 4n7 is 4.7 nF, n47 is 470 pF and 4µ7 (or 4u7) is 4.7 µF. The tool reads these formats, shows the value in pF, nF, µF and mF, and goes the other way: given a value, it returns the code.

How to use

Type what is printed and read the value, or start from the value and find the code

In Read code mode, type what is printed on the capacitor: 104, 473K, 4n7, 2R2. The shortcuts show common examples.
Read the capacitance in nF, µF, pF and mF, the RKM notation and the tolerance range when there is a letter.
In Value to code mode, type a value and unit to get the 3-digit code. The table below lists the E6 series values; click a code to load it.

Examples

The most searched codes

Applying the rule XY × 10^Z pF: 101 = 10 × 10¹ = 100 pF; 102 = 1,000 pF = 1 nF; 103 = 10,000 pF = 10 nF = 0.01 µF; 104 = 100,000 pF = 100 nF = 0.1 µF; 105 = 1,000,000 pF = 1 µF. With other digit pairs: 473 = 47 × 10³ pF = 47 nF; 224 = 22 × 10⁴ pF = 220 nF = 0.22 µF; 106 = 10 µF.

The reverse works the same way. For 150 nF (150,000 pF) write 15 × 10⁴, which is 154. For 4.7 µF (4,700,000 pF) write 47 × 10⁵, which is 475. When the value has three significant digits, such as 123 nF, there is no exact code: the nearest is 124 (120 nF), and the tool shows the difference.

1 µF = 1,000 nF = 1,000,000 pF
1 nF = 1,000 pF
104 = 100 nF = 0.1 µF
473 = 47 nF = 0.047 µF

Notations

The R letter, RKM notation and prefixes

RKM notation, described in the IEC 60062 standard, replaces the decimal point with the prefix: 4n7 is 4.7 nF, 2p2 is 2.2 pF, 4µ7 is 4.7 µF, 100n is 100 nF. The prefix is lowercase (p, n, µ, m); the uppercase F is farad. On low-value capacitors, the letter R also acts as the decimal point: 2R2 is 2.2 pF and 4R7 is 4.7 pF.

Some manufacturers use 8 and 9 as the third digit for values below 10 pF, with multipliers of ×0.01 and ×0.1. By that convention, 479 would be 4.7 pF. The tool decodes it but flags the result as a convention and asks you to confirm in the datasheet, because not every source documents it.

Limits

What the code does not say

The 3-digit code gives the capacitance and, with the letter, the tolerance. It does not give the maximum working voltage or the dielectric: Wikipedia shows the example 473K 330V, where the voltage is written separately. Voltage codes made of a letter and a digit (such as 1H) vary by manufacturer and this tool does not decode them. When replacing a capacitor, also check the voltage and type in the datasheet.

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References

Sources and references for this tool

These references help contextualize formulas, standards, APIs and limitations used on this page. They do not replace professional validation when a result has legal, financial, medical or operational impact.

FAQ

Frequently asked questions

What is the value of a 104 capacitor?

104 is 10 × 10⁴ pF = 100,000 pF, which is 100 nF or 0.1 µF. It is not 104 pF. The same holds for other codes: the first two digits are the value and the third is the number of zeros.

How do I read a capacitor's 3-digit code?

What are capacitors 102, 103, 105, 224 and 473 worth?

What do the letters J, K and M after the code mean?

How do I convert pF, nF and µF?

What is 4n7, n47 or 4u7 on a capacitor?

What does 2R2 or 4R7 mean on a capacitor?

And a third digit of 8 or 9, as in 479?

Does the code give the capacitor's voltage?

How do I find the code for a 220 nF or 0.15 µF capacitor?

Chemistry & Physics

Value	RKM	pF
10 pF	10p	10
15 pF	15p	15
22 pF	22p	22
33 pF	33p	33
47 pF	47p	47
68 pF	68p	68
100 pF	100p	100
150 pF	150p	150
220 pF	220p	220
330 pF	330p	330
470 pF	470p	470
680 pF	680p	680
1 nF	1n	1,000
1.5 nF	1n5	1,500
2.2 nF	2n2	2,200
3.3 nF	3n3	3,300
4.7 nF	4n7	4,700
6.8 nF	6n8	6,800
10 nF	10n	10,000
15 nF	15n	15,000
22 nF	22n	22,000
33 nF	33n	33,000
47 nF	47n	47,000
68 nF	68n	68,000
100 nF	100n	100,000
150 nF	150n	150,000
220 nF	220n	220,000
330 nF	330n	330,000
470 nF	470n	470,000
680 nF	680n	680,000
1 µF	1µ	1,000,000
1.5 µF	1µ5	1,500,000
2.2 µF	2µ2	2,200,000
3.3 µF	3µ3	3,300,000
4.7 µF	4µ7	4,700,000
6.8 µF	6µ8	6,800,000
10 µF	10µ	10,000,000

Value	RKM	pF
10 pF	10p	10
15 pF	15p	15
22 pF	22p	22
33 pF	33p	33
47 pF	47p	47
68 pF	68p	68
100 pF	100p	100
150 pF	150p	150
220 pF	220p	220
330 pF	330p	330
470 pF	470p	470
680 pF	680p	680
1 nF	1n	1,000
1.5 nF	1n5	1,500
2.2 nF	2n2	2,200
3.3 nF	3n3	3,300
4.7 nF	4n7	4,700
6.8 nF	6n8	6,800
10 nF	10n	10,000
15 nF	15n	15,000
22 nF	22n	22,000
33 nF	33n	33,000
47 nF	47n	47,000
68 nF	68n	68,000
100 nF	100n	100,000
150 nF	150n	150,000
220 nF	220n	220,000
330 nF	330n	330,000
470 nF	470n	470,000
680 nF	680n	680,000
1 µF	1µ	1,000,000
1.5 µF	1µ5	1,500,000
2.2 µF	2µ2	2,200,000
3.3 µF	3µ3	3,300,000
4.7 µF	4µ7	4,700,000
6.8 µF	6µ8	6,800,000
10 µF	10µ	10,000,000

Capacitor Code Calculator