Capacitor Code Calculator

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4n7 capacitor value

4n7 capacitor: RKM notation explained

In 4n7 the letter n sits where the decimal point would be and names the unit at the same time: it means 4.7 nF, or 4,700 pF. In 3-digit marking the same capacitor appears as 472. The notation is called RKM and appears in the IEC 60062 standard.

How to read and write RKM

The prefix stands in for the point: whatever comes before the letter is the whole part and whatever follows is the decimals. So 4n7 is 4 + 0.7 = 4.7 nF = 4,700 pF = 47 × 10^2, code 472. The n47 is 0.47 nF = 470 pF, code 471. The 4u7 (or 4µ7) is 4.7 µF = 4,700,000 pF, code 475. The lowercase letters p, n, µ and m mark the prefix, while a capital F is the farad and may be left off.
The reason it exists is practical: a decimal point is tiny and vanishes easily in cramped print, on a photocopied schematic or on a worn part, while a letter in the middle of the digits survives better. The letter also carries the unit, so there is no loose 4.7 left to be read as pF, nF or µF. Watch 4n7 against 47n: the first is 4.7 nF, the second is 47 nF, ten times larger.
Below 10 pF the 3-digit code uses the letter R as the decimal point: 2R2 is 2.2 pF. That sidesteps the trap of 220, which with a power of zero is 22 pF, not 2.2. The same part in RKM would be 2p2. Entering 100nF in the tool (with the F, not just 100n) returns the code 104; 2p2 becomes 2R2, and 4u7 becomes 475.

RKM to 3-digit code

4n7 itself

Input: 4n7
Expected output: 472

4.7 nF = 4,700 pF = 47 × 10^2.

Prefix before the decimals

Input: n47
Expected output: 471

0.47 nF = 470 pF = 47 × 10^1.

Microfarad in RKM

Input: 4u7
Expected output: 475

4.7 µF = 4,700,000 pF = 47 × 10^5.

Picofarad with a decimal

Input: 2p2
Expected output: 2R2

2.2 pF; below 10 pF the code uses R.

With the F spelled out

Input: 100nF
Expected output: 104

100 nF = 100,000 pF = 10 × 10^4.

Full tool FAQ

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?

Frequently asked questions

Is a 4n7 capacitor 4.7 nF or 47 nF?

It is 4.7 nF. The n sits where the point would be, with the 4 before and the 7 after. For 47 nF the RKM marking would be 47n, and the 3-digit code would be 473.

What is the 3-digit code of a 4n7?

It is 472: 4.7 nF is 4,700 pF, written as 47 × 10^2. The reverse reading holds as well, since 472 gives 4n7 in RKM notation.

Are n47 and 4n7 the same value?

No. In n47 there is no whole part, so it means 0.47 nF, or 470 pF (code 471). The 4n7 has 4 whole units and is worth ten times as much.

What is the difference between 2R2 and 220?

The 2R2 is 2.2 pF, with R acting as the point. The 220 is 22 × 10^0 = 22 pF. In RKM, the first is 2p2 and the second is 22p.

Next steps

C	±0.25 pF
D	±0.5 pF
J	±5%
K	±10%
M	±20%
Z	−20% / +80%

±0.25 pF

±0.5 pF

±5%

±10%

±20%

−20% / +80%

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

Code

RKM

10 pF

10p

15 pF

15p

22 pF

22p

33 pF

33p

47 pF

47p

68 pF

68p

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

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

How to read and write RKM

The prefix stands in for the point: whatever comes before the letter is the whole part and whatever follows is the decimals. So 4n7 is 4 + 0.7 = 4.7 nF = 4,700 pF = 47 × 10^2, code 472. The n47 is 0.47 nF = 470 pF, code 471. The 4u7 (or 4µ7) is 4.7 µF = 4,700,000 pF, code 475. The lowercase letters p, n, µ and m mark the prefix, while a capital F is the farad and may be left off.

The reason it exists is practical: a decimal point is tiny and vanishes easily in cramped print, on a photocopied schematic or on a worn part, while a letter in the middle of the digits survives better. The letter also carries the unit, so there is no loose 4.7 left to be read as pF, nF or µF. Watch 4n7 against 47n: the first is 4.7 nF, the second is 47 nF, ten times larger.

Below 10 pF the 3-digit code uses the letter R as the decimal point: 2R2 is 2.2 pF. That sidesteps the trap of 220, which with a power of zero is 22 pF, not 2.2. The same part in RKM would be 2p2. Entering 100nF in the tool (with the F, not just 100n) returns the code 104; 2p2 becomes 2R2, and 4u7 becomes 475.

RKM to 3-digit code

4n7 itself

Input: 4n7
Expected output: 472

4.7 nF = 4,700 pF = 47 × 10^2.

Prefix before the decimals

Input: n47
Expected output: 471

0.47 nF = 470 pF = 47 × 10^1.

Microfarad in RKM

Input: 4u7
Expected output: 475

4.7 µF = 4,700,000 pF = 47 × 10^5.

Picofarad with a decimal

Input: 2p2
Expected output: 2R2

2.2 pF; below 10 pF the code uses R.

With the F spelled out

Input: 100nF
Expected output: 104

100 nF = 100,000 pF = 10 × 10^4.

Full tool FAQ

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?

Frequently asked questions

Is a 4n7 capacitor 4.7 nF or 47 nF?

It is 4.7 nF. The n sits where the point would be, with the 4 before and the 7 after. For 47 nF the RKM marking would be 47n, and the 3-digit code would be 473.

What is the 3-digit code of a 4n7?

It is 472: 4.7 nF is 4,700 pF, written as 47 × 10^2. The reverse reading holds as well, since 472 gives 4n7 in RKM notation.

Are n47 and 4n7 the same value?

No. In n47 there is no whole part, so it means 0.47 nF, or 470 pF (code 471). The 4n7 has 4 whole units and is worth ten times as much.

What is the difference between 2R2 and 220?

The 2R2 is 2.2 pF, with R acting as the point. The 220 is 22 × 10^0 = 22 pF. In RKM, the first is 2p2 and the second is 22p.

Capacitor Code Calculator

Continue in the tool

More pages for this tool

4n7 capacitor: RKM notation explained

How to read and write RKM

RKM to 3-digit code

4n7 itself

Prefix before the decimals

Microfarad in RKM

Picofarad with a decimal

With the F spelled out

Full tool FAQ

Frequently asked questions

Is a 4n7 capacitor 4.7 nF or 47 nF?

What is the 3-digit code of a 4n7?

Are n47 and 4n7 the same value?

What is the difference between 2R2 and 220?

Next steps

Capacitor Code Calculator

E6 series values, 10 pF to 10 µF

Continue in the tool

More pages for this tool

4n7 capacitor: RKM notation explained

How to read and write RKM

RKM to 3-digit code

4n7 itself

Prefix before the decimals

Microfarad in RKM

Picofarad with a decimal

With the F spelled out

Full tool FAQ

Frequently asked questions

Is a 4n7 capacitor 4.7 nF or 47 nF?

What is the 3-digit code of a 4n7?

Are n47 and 4n7 the same value?

What is the difference between 2R2 and 220?

Next steps

E6 series values, 10 pF to 10 µF