Capacitance Converter (F, µF, nF, pF)

Understanding the capacitance converter — concept and principle

Capacitance tells you how much electric charge a component stores per volt. Real capacitors span an enormous range, from a few picofarads in radio circuits to thousands of microfarads in power supplies, so values are written with SI prefixes and printed in several styles. This converter moves a value between farads, millifarads, microfarads, nanofarads and picofarads, which helps when a schematic says 0.1 µF but the parts list or the capacitor body says 100 nF or 104.

How it is calculated

Each unit is a power of ten of the farad (F):

• 1 mF = 10⁻³ F
• 1 µF = 10⁻⁶ F
• 1 nF = 10⁻⁹ F
• 1 pF = 10⁻¹² F

result = value × (farads per "from" unit) ÷ (farads per "to" unit). Neighboring prefixes differ by a factor of 1,000, so moving one step toward a smaller unit multiplies by 1,000 and one step toward a larger unit divides by 1,000.

The principle

A capacitor is two conductors separated by an insulator. Its capacitance is C = Q ÷ V: the charge Q (coulombs) stored for each volt V across it. One farad means one coulomb per volt, which is very large for ordinary parts, so engineers almost always work in µF, nF or pF. SI prefixes are defined exactly, so every conversion here is exact; only the display is rounded.

Worked example

Default: 1 nF to µF.

1. 1 nF = 1 × 10⁻⁹ F.
2. 1 µF = 1 × 10⁻⁶ F.
3. 10⁻⁹ ÷ 10⁻⁶ = 10⁻³, so 1 nF = 0.001 µF.
4. The same value is 1,000 pF, 1 × 10⁻⁹ F and 0.000001 mF.

How to read the result

Typical ranges help you sanity-check a value: tens to hundreds of pF for oscillator and RF parts, 10 nF to 100 nF (0.01–0.1 µF) for decoupling next to chips, and 1 µF to several thousand µF for filtering and power supplies. Supercapacitors reach whole farads. Ceramic capacitors often carry a three-digit code in picofarads: two significant digits and a multiplier, so 104 = 10 × 10⁴ pF = 100 nF = 0.1 µF, and 472 = 4.7 nF.

Common mistakes

• Typing "u" or "mu" for µ and then reading "m" (milli) by accident; 1 mF is 1,000 µF.
• Reading old schematics where "mF" or "MFD" meant microfarad, not millifarad.
• Forgetting the tolerance: a 100 nF ceramic may be ±10% or ±20%, and some ceramic types lose capacitance with DC voltage and temperature.

FAQ

Frequently asked questions

Is 0.1 µF the same as 100 nF?

Yes, exactly; both are 100,000 pF and usually marked 104.

How many pF are in 1 µF?

1,000,000 pF.

What does "4n7" mean on a schematic?

It is 4.7 nF; the letter replaces the decimal point to avoid misreading.

Sources: BIPM, The International System of Units (SI Brochure), 9th edition · IEC 60062 Marking codes for resistors and capacitors