473 capacitor value
47 nF
47,000 pF · 47 nF · 0.047 µF
| Marked code | 473 |
| Picofarads | 47,000 pF |
| Nanofarads | 47 nF |
| Microfarads | 0.047 µF |
| Farads | 4.70e-8 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:
47 × 103 = 47,000 pF
So 473 is 47 followed by 3 zeros: 47,000 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 473 is stocked as 0.047 µF and the two numbers look nothing alike.
What 47 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 47 nF part covers several orders of magnitude:
| Frequency | Reactance |
|---|---|
| 50 Hz — mains | 67.73 kΩ |
| 1 kHz — audio | 3.39 kΩ |
| 100 kHz — switching | 33.86 Ω |
| 10 MHz — RF | 338.6 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 473K carries a tolerance letter. It is not part of the value:
| Letter | Tolerance | 47 nF means |
|---|---|---|
473J | ±5% | 44.65 nF to 49.35 nF |
473K | ±10% | 42.3 nF to 51.7 nF |
473M | ±20% | 37.6 nF to 56.4 nF |
473Z | +80% / −20% | 37.6 nF to 84.6 nF |
A Z is worth knowing about. +80%/−20% is a real tolerance on cheap high-permittivity ceramics, and it means a part marked 473Z can legitimately be anything from 37.6 nF to 84.6 nF. Those go in decoupling positions where only the rough size matters, never in a timing or filter position.
Where 47 nF turns up
Tens of nanofarads is coupling between audio stages and the smaller decoupling capacitors on a logic board. A 10 nF part alongside a 100 nF one is a common pairing, the smaller of the two handling the frequencies the larger one is too slow for.
Frequently asked questions
What is the value of a 473 capacitor?
47 nF — 47,000 pF · 47 nF · 0.047 µF. The first two digits are the value in picofarads and the third is how many zeros follow, so 473 is 47 followed by 3 zeros = 47,000 pF.
What is a 473 capacitor in µF?
0.047 µF. Going from picofarads to microfarads is six decimal places, which is where most of the confusion with these codes comes from — 47,000 pF, 47 nF and 0.047 µF are the same capacitor written three ways.
What does the letter after 473 mean?
Tolerance. 473K is ±10%, 473J is ±5% and 473M is ±20% — so a 473K is anywhere from 42.3 nF to 51.7 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 473 capacitor at 1 kHz?
3.39 kΩ. Reactance is 1 ÷ (2πfC), so it falls as the frequency rises: the same part is 33.86 Ω at 100 kHz and 338.6 mΩ at 10 MHz.
Nearby codes
- 563 capacitor — 56 nF
- 683 capacitor — 68 nF
- 823 capacitor — 82 nF
- 104 capacitor — 100 nF
- 124 capacitor — 120 nF
- 154 capacitor — 150 nF
- 184 capacitor — 180 nF
- 224 capacitor — 220 nF
- 274 capacitor — 270 nF
- 334 capacitor — 330 nF