332 capacitor value
3.3 nF
3,300 pF · 3.3 nF · 0.0033 µF
| Marked code | 332 |
| Picofarads | 3,300 pF |
| Nanofarads | 3.3 nF |
| Microfarads | 0.0033 µF |
| Farads | 3.30e-9 F |
Reading the code
The three digits are not a part number. The first two are the value in picofarads and the third says what to do with them:
33 × 102 = 3,300 pF
So 332 is 33 followed by 2 zeros: 3,300 pF. The code is always in picofarads even when the part is sold in microfarads, which is the whole difficulty with it — a capacitor marked 332 is stocked as 0.0033 µF and the two numbers look nothing alike.
What 3.3 nF does at frequency
A capacitor's opposition to a signal is its reactance, 1 ÷ (2πfC), and it falls as the frequency rises. Over the range of frequencies a circuit can put across it, a 3.3 nF part covers several orders of magnitude:
| Frequency | Reactance |
|---|---|
| 50 Hz — mains | 964.58 kΩ |
| 1 kHz — audio | 48.23 kΩ |
| 100 kHz — switching | 482.29 Ω |
| 10 MHz — RF | 4.82 Ω |
Ten times the frequency is a tenth of the reactance, every time — which is why choosing a decoupling capacitor is really choosing the frequency band you want it to be low-impedance across, and why boards carry several sizes in parallel rather than one large one.
The letter after the number
A code like 332K carries a tolerance letter. It is not part of the value:
| Letter | Tolerance | 3.3 nF means |
|---|---|---|
332J | ±5% | 3.135 nF to 3.465 nF |
332K | ±10% | 2.97 nF to 3.63 nF |
332M | ±20% | 2.64 nF to 3.96 nF |
332Z | +80% / −20% | 2.64 nF to 5.94 nF |
A Z is worth knowing about. +80%/−20% is a real tolerance on cheap high-permittivity ceramics, and it means a part marked 332Z can legitimately be anything from 2.64 nF to 5.94 nF. Those go in decoupling positions where only the rough size matters, never in a timing or filter position.
Where 3.3 nF turns up
Single-figure nanofarads is audio filtering and snubbing across switch contacts. It is also the range where a capacitor stops being a precision component and starts being a bypass, depending on the dielectric it is made from.
Frequently asked questions
What is the value of a 332 capacitor?
3.3 nF — 3,300 pF · 3.3 nF · 0.0033 µF. The first two digits are the value in picofarads and the third is how many zeros follow, so 332 is 33 followed by 2 zeros = 3,300 pF.
What is a 332 capacitor in µF?
0.0033 µF. Going from picofarads to microfarads is six decimal places, which is where most of the confusion with these codes comes from — 3,300 pF, 3.3 nF and 0.0033 µF are the same capacitor written three ways.
What does the letter after 332 mean?
Tolerance. 332K is ±10%, 332J is ±5% and 332M is ±20% — so a 332K is anywhere from 2.97 nF to 3.63 nF and still in specification. A Z means +80%/−20%, which is not a mistake: some ceramic dielectrics really are that loose.
What is the impedance of a 332 capacitor at 1 kHz?
48.23 kΩ. Reactance is 1 ÷ (2πfC), so it falls as the frequency rises: the same part is 482.29 Ω at 100 kHz and 4.82 Ω at 10 MHz.
Nearby codes
- 392 capacitor — 3.9 nF
- 472 capacitor — 4.7 nF
- 562 capacitor — 5.6 nF
- 682 capacitor — 6.8 nF
- 822 capacitor — 8.2 nF
- 103 capacitor — 10 nF
- 123 capacitor — 12 nF
- 153 capacitor — 15 nF
- 183 capacitor — 18 nF
- 223 capacitor — 22 nF