Capacitance Converter
What is a Farad?
A Capacitor is an electronic component that stores electrical energy in an electric field. Think of it as a small, temporary battery.
The unit of capacitance is the Farad (F), named after physicist Michael Faraday. However, 1 Farad is an absolutely massive amount of capacitance. The Earth itself only has a capacitance of about 0.0007 Farads (710 µF).
Because the base unit is so huge, electronics engineers almost exclusively work with tiny subdivisions: Micro, Nano, and Pico.
The 3 Common Units
Converting between these units can be confusing because you are moving the decimal point by groups of 3.
1. Microfarad ($\mu$F or uF)
This is $10^{-6}$ Farads. Used in power supplies and audio filters.
1 F = 1,000,000 µF.
2. Nanofarad (nF)
This is $10^{-9}$ Farads. Used in timing circuits and sensors.
1 µF = 1,000 nF.
3. Picofarad (pF)
This is $10^{-12}$ Farads. Used in high-frequency radio (RF) circuits.
1 nF = 1,000 pF.
Micro > Nano > Pico.
Each step is a difference of 1,000. To go from $\mu$F to nF, multiply by 1,000. To go from nF to $\mu$F, divide by 1,000.
How to Read Capacitor Codes (103, 104)
Small ceramic capacitors are too tiny to print "0.1 µF" on them. Instead, they use a 3-digit code. Reading this code is a vital skill for DIY electronics.
The system works like this: Digit 1, Digit 2, Multiplier.
The resulting number is always in Picofarads (pF).
| Code | Calculation (pF) | Result (nF / µF) |
|---|---|---|
| 103 | 10 + 3 zeros = 10,000 pF | 10 nF / 0.01 µF |
| 104 | 10 + 4 zeros = 100,000 pF | 100 nF / 0.1 µF |
| 472 | 47 + 2 zeros = 4,700 pF | 4.7 nF / 0.0047 µF |
| 221 | 22 + 1 zero = 220 pF | 0.22 nF / 0.00022 µF |
Capacitors in Series vs. Parallel
If you are building a circuit, remember that capacitors behave the opposite of resistors.
- Parallel: Capacitance adds up. (C = C1 + C2). Putting two 100µF caps side-by-side acts like one big 200µF cap.
- Series: Capacitance decreases. (1/C = 1/C1 + 1/C2). Putting two 100µF caps in a line creates a 50µF equivalent.