Capacitor Code Calculator

Type a code like 104 or 4R7 to get the capacitance — or a capacitance to get the code — tolerance letters included.

Capacitor code

Picofarads

Nanofarads

Microfarads

Tolerance

Capacitance → code

Capacitance

Tolerance letter

Code

How the 3-digit code works

Small capacitors don't have room for "0.1 µF", so they carry a compact EIA code: two significant digits and a multiplier, in picofarads. 104 means 10 × 10⁴ pF = 100,000 pF = 100 nF = 0.1 µF. For values under 10 pF an R marks the decimal point: 4R7 is 4.7 pF. A trailing letter, when present, is the tolerance — 473K is 47 nF ±10%.

Common codes

Code	pF	nF	µF
100	10	0.01	0.00001
101	100	0.1	0.0001
102	1,000	1	0.001
103	10,000	10	0.01
104	100,000	100	0.1
105	1,000,000	1,000	1
221	220	0.22	—
473	47,000	47	0.047
684	680,000	680	0.68

Tolerance letters

Letter	Tolerance
B / C / D	±0.1 / ±0.25 / ±0.5 pF (small values)
F / G	±1% / ±2%
J	±5%
K	±10%
M	±20%
Z	+80% / −20%

Frequently asked questions

Why picofarads?: The code was standardized when typical ceramic capacitors were all in the pF–nF range; pF keeps the exponent a single digit for everything up to tens of µF.
My capacitor just says "47". What is it?: One- and two-digit markings are the value in pF directly — 47 pF. The three-digit multiplier form always has that third digit.
What about electrolytics?: Electrolytic and larger film capacitors have room to print the real value ("470 µF 25 V"), so they skip the code entirely.
Is K kilo?: Not here — a trailing K is ±10% tolerance. That's why 473K is 47 nF, not 473,000 of anything. A common trap.