106 capacitor value
10 µF
10,000,000 pF · 10000 nF · 10 µF
| Marked code | 106 |
| Picofarads | 10,000,000 pF |
| Nanofarads | 10000 nF |
| Microfarads | 10 µF |
| Farads | 1.00e-5 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:
10 × 106 = 10,000,000 pF
So 106 is 10 followed by 6 zeros: 10,000,000 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 106 is stocked as 10 µF and the two numbers look nothing alike.
What 10 µF 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 10 µF part covers several orders of magnitude:
| Frequency | Reactance |
|---|---|
| 50 Hz — mains | 318.31 Ω |
| 1 kHz — audio | 15.92 Ω |
| 100 kHz — switching | 159.2 mΩ |
| 10 MHz — RF | 1.6 mΩ |
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 106K carries a tolerance letter. It is not part of the value:
| Letter | Tolerance | 10 µF means |
|---|---|---|
106J | ±5% | 9.5 µF to 10.5 µF |
106K | ±10% | 9 µF to 11 µF |
106M | ±20% | 8 µF to 12 µF |
106Z | +80% / −20% | 8 µF to 18 µF |
A Z is worth knowing about. +80%/−20% is a real tolerance on cheap high-permittivity ceramics, and it means a part marked 106Z can legitimately be anything from 8 µF to 18 µF. Those go in decoupling positions where only the rough size matters, never in a timing or filter position.
Where 10 µF turns up
Microfarads and up is bulk energy storage: holding a rail up between switching cycles, smoothing a supply, or coupling a signal that goes down to a few hertz. Above about 10 µF ceramics give way to electrolytics and tantalums, which is why the code runs out here.
Frequently asked questions
What is the value of a 106 capacitor?
10 µF — 10,000,000 pF · 10000 nF · 10 µF. The first two digits are the value in picofarads and the third is how many zeros follow, so 106 is 10 followed by 6 zeros = 10,000,000 pF.
What is a 106 capacitor in µF?
10 µF. Going from picofarads to microfarads is six decimal places, which is where most of the confusion with these codes comes from — 10,000,000 pF, 10000 nF and 10 µF are the same capacitor written three ways.
What does the letter after 106 mean?
Tolerance. 106K is ±10%, 106J is ±5% and 106M is ±20% — so a 106K is anywhere from 9 µF to 11 µF 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 106 capacitor at 1 kHz?
15.92 Ω. Reactance is 1 ÷ (2πfC), so it falls as the frequency rises: the same part is 159.2 mΩ at 100 kHz and 1.6 mΩ at 10 MHz.
Nearby codes
- 126 capacitor — 12 µF
- 156 capacitor — 15 µF
- 186 capacitor — 18 µF
- 226 capacitor — 22 µF
- 276 capacitor — 27 µF
- 336 capacitor — 33 µF
- 396 capacitor — 39 µF
- 476 capacitor — 47 µF
- 566 capacitor — 56 µF
- 686 capacitor — 68 µF