Capacitance converter — pF, nF, µF and farads

How to use the capacitance converter

1. Type the value in Value. For a capacitor code, decode it to picofarads first (see the FAQ).
2. In From, choose the unit you have.
3. In To, choose the unit the datasheet, shop or schematic uses.
4. Read the answer, or scan the table for all seven units. The swap button reverses the direction.

What it does and when to use it

Capacitor values are written in at least three prefixes. Small ceramic parts are marked in picofarads, film parts in nanofarads, and electrolytics in microfarads. Shops and schematics do not always agree. A 100 nF decoupling capacitor might be listed as 0.1 µF, “104” or 100,000 pF. This converter removes the guesswork. It also covers the farad itself, which you will see on supercapacitors, and two CGS units from older physics texts.

It is useful next to the resistance converter when you design RC filters and timers, and the inductance converter for LC circuits. Once you know the frequency of an LC circuit, the frequency ↔ wavelength converter gives its wavelength.

How it works

The farad is the base. Each unit has a factor in farads, and the result is value × from-factor ÷ to-factor.

c is the speed of light, exactly 299,792,458 m/s. The SI prefixes are exact powers of ten.

Worked examples

Code 104. 100 nF = 0.1 microfarads. That is the classic decoupling capacitor next to almost every chip.

Code 472. 4,700 pF = 4.7 nanofarads, a common value in filters and snubbers.

CGS unit. 1 statfarad = 1.11265005605 picofarads. An isolated metal sphere 1 cm in radius has a capacitance of 1 statfarad, which shows how small this unit is.

Limits and tips

• Tolerance and voltage are separate from the value. A part marked 104K is 100 nF ±10 %, and the voltage rating must also match your circuit.
• Codes are not typed in directly. Enter the decoded value, not “104”.
• Values below 1e-9 of a unit show in scientific notation, for example 1 pF is 1e-12 F.