Capacitance Calculator

Capacitor values move across several prefixes in everyday electronics. A power rail bypass part may be labeled 0.1 µF, a timing capacitor may be 47 nF, and an RF matching part may be 12 pF. This calculator converts those values without changing the physical capacitance. Enter a nonnegative Value, select the From unit, choose the To unit, and the result panel reports the requested conversion plus all supported equivalents.

Capacitance is the ability of a component or structure to store electric charge for a given voltage. The SI unit is the farad, symbol F. One farad is large enough that ordinary circuit parts usually use submultiples: millifarads for some large electrolytics and supercapacitors, microfarads for power filtering, nanofarads for timing and decoupling, and picofarads for RF, crystal load, stray, and sensor capacitances. The converter does not estimate tolerance or circuit behavior; it only applies the unit factors used in the calculation.

Factors used by the converter

The calculator converts through farads. First it multiplies by the source unit’s factor, then it divides by the target unit’s factor:

$\text{capacitance in farads} = \text{value} \text{ } \times \text{ } \text{source factor}$

$\text{converted capacitance} = \frac{\text{capacitance in farads}}{\text{target factor}}$

The converter accepts values from 0 through 1,000,000,000,000 in the selected unit and formats results with up to 12 decimal places. Very large or very small values may be easier to compare by choosing a prefix close to the component’s marked value.

Capacitance example

Convert 4.7 µF to nanofarads. The source factor for microfarads is 0.000001:

$4.7 \text{ } \mu\text{F} \text{ } \times \text{ } 0.000001 = 0.0000047 \text{ } \text{F}$

The target factor for nanofarads is 0.000000001, so the calculator divides:

$\frac{0.0000047}{0.000000001} = 4{,}700$

The selected result is 4,700 nF. The same entry appears as 0.0047 mF, 4.7 µF, and 4,700,000 pF in the all-units list. If you later need to combine that capacitance with voltage, current, or resistance, use the ohms law calculator, power converter, or electric current converter for the related electrical quantities.

Practical unit guide

Farads and millifarads appear with energy storage, hold-up capacitors, and supercapacitors. In those applications, stored energy, leakage, balancing, temperature range, and surge limits matter as much as the nominal value.

Microfarads are common in power supplies, audio coupling, bulk decoupling, and electrolytic or tantalum capacitors. A 10 µF part is 10,000 nF or 10,000,000 pF, but writing it in µF is clearer.

Nanofarads bridge general electronics and timing work. Values such as 1 nF, 10 nF, 47 nF, and 100 nF appear in RC filters, debouncing circuits, and local decoupling.

Picofarads suit radio-frequency design, oscillator load capacitors, small ceramic parts, cable capacitance, probe loading, and parasitic estimates. A seemingly tiny difference of a few pF can shift a resonant circuit.

Reference table

Common mistakes

• Reading µF as mF. Millifarads are 1,000 times larger than microfarads.
• Treating a conversion as a guarantee of interchangeability. Voltage rating, dielectric, ESR, ripple current, and polarity still matter.
• Ignoring tolerance. A 100 nF capacitor with 20% tolerance can legitimately measure well above or below 100 nF.
• Forgetting that layout adds capacitance. In RF and high-impedance sensor circuits, pads, cables, probes, and nearby conductors can be significant.
• Mixing capacitor units while calculating time constants. Convert to farads before using resistance and capacitance together.

For broader circuit checks, keep unit conversions separate from design formulas. The energy converter can help when stored energy is reported in joules, and the frequency converter is a useful companion for RC or RF discussions that involve hertz.

One more source of confusion is printed capacitor codes. A three-digit ceramic code such as 104 usually means 10 followed by 4 zeros in picofarads, or 100,000 pF, which is 100 nF and 0.1 µF. A code such as 220 means 22 pF, not 220 nF, because the last digit is the multiplier. This converter is a good final check after translating the marking, especially when a schematic, bill of materials, and replacement part listing use different prefixes.

Sources

• NIST, SI Units — SI unit framework and derived-unit context.
• NIST, SI Prefixes — milli, micro, nano, and pico prefix values.
• BIPM, Measurement units — international SI reference maintained by the BIPM.