Capacitor Code Calculator
Type the code printed on a ceramic, film or tantalum capacitor (like 104, 472J or 4R7) to get its value in pF, nF and µF with tolerance, or enter a value to find its code.
Accepts 3-digit codes (104), 2-digit codes (47), R decimals (4R7), 4n7 / 2u2 style, an optional tolerance letter (J, K, M…) and a voltage code (2A, 1H…).
––––Common capacitor codes Click a row to decode it
| Code | pF | nF | µF |
|---|
How to use the Capacitor Code Calculator
- Type the code printed on the capacitor, for example 104, 472J or 2A223K.
- Read the value in pF, nF and µF. The steps underneath explain how the digits were decoded.
- Check the tolerance and voltage: letters in the code are read automatically, or pick them from the lists.
- Switch to Value → code to enter a capacitance such as 0.1 µF and press Convert to code to get the marking to look for.
- Click a row in the common codes table to decode it, or press Copy next to any value.
How capacitor codes work
Small capacitors are too small for a full value, so makers print a short code based on picofarads (pF). The first two digits are the significant figures and the third digit is the multiplier (the number of zeros):
- 104 = 10 × 10⁴ = 100,000 pF = 100 nF = 0.1 µF
- 472 = 47 × 10² = 4,700 pF = 4.7 nF
- 221 = 22 × 10¹ = 220 pF
- 229 = 22 × 0.1 = 2.2 pF (9 means × 0.1, 8 means × 0.01)
Values under 100 pF are often printed as plain numbers (47 = 47 pF), and values under 10 pF use R as a decimal point (4R7 = 4.7 pF). Some film capacitors print the unit as the decimal point instead, such as 4n7 for 4.7 nF or 2u2 for 2.2 µF.
Tolerance letter codes
| Letter | Tolerance | Letter | Tolerance |
|---|---|---|---|
| B | ±0.1 pF (≤10 pF) or ±0.1% | G | ±2% |
| C | ±0.25 pF (≤10 pF) or ±0.25% | J | ±5% |
| D | ±0.5 pF (≤10 pF) or ±0.5% | K | ±10% |
| F | ±1% | M | ±20% |
| Z | +80% / −20% | ||
Common voltage codes
| Code | Voltage | Code | Voltage | Code | Voltage |
|---|---|---|---|---|---|
| 0J | 6.3 V | 1H | 50 V | 2D | 200 V |
| 1A | 10 V | 1J | 63 V | 2E | 250 V |
| 1C | 16 V | 2A | 100 V | 2G | 400 V |
| 1E | 25 V | 2C | 160 V | 2J | 630 V |
The voltage code is the maximum continuous DC voltage. Choose a capacitor rated comfortably above the highest voltage in your circuit; for ceramic capacitors twice the working voltage is a common rule of thumb because their capacitance drops under DC bias.
Tips for reading markings
- Electrolytic capacitors print the value and voltage in full (for example 470 µF 25 V) and don't use these codes.
- A 3-digit code can only hold two significant figures, so values like 4.75 nF can't be coded exactly.
- If the code ends in 7, you are probably misreading a 1, because 7 isn't used as a multiplier.
Frequently asked questions
What is the value of a 104 capacitor?
104 means 10 followed by 4 zeros picofarads: 10 × 10,000 = 100,000 pF, which is 100 nF or 0.1 µF. It is the most common decoupling capacitor value.
How do I read a 3-digit capacitor code?
The first two digits are the significant figures and the third digit is the number of zeros to add, giving the value in picofarads. A third digit of 8 means multiply by 0.01 and 9 means multiply by 0.1.
What does the letter after the code mean?
It is the tolerance: F = ±1%, G = ±2%, J = ±5%, K = ±10%, M = ±20% and Z = +80% / −20%. B, C and D mean ±0.1, ±0.25 and ±0.5 pF on small capacitors of 10 pF or less.
What does 4R7 mean on a capacitor?
The R stands for the decimal point, so 4R7 is 4.7 pF. The same style is used for other small values, such as 1R0 for 1 pF or R47 for 0.47 pF.
How do I convert pF to nF and µF?
1 nF = 1,000 pF and 1 µF = 1,000 nF = 1,000,000 pF. So 4,700 pF = 4.7 nF = 0.0047 µF.
What do codes like 1H or 2A mean?
They are EIA voltage codes giving the maximum working voltage, for example 1C = 16 V, 1E = 25 V, 1H = 50 V, 2A = 100 V and 2J = 630 V.