Capacitance Conversion Calculator

Use this calculator to convert capacitance values between farads, millifarads, microfarads, nanofarads, picofarads, and other supported units. It can also help decode common three-digit capacitor value codes such as 104 or 472 when the code follows the picofarad marking convention.

Unit conversion and component marking are different tasks. A capacitance unit has a defined SI scale factor, while markings printed on a capacitor may also contain tolerance, rated voltage, dielectric, series, date, or manufacturer-specific information. Verify an actual component against its datasheet whenever identification matters.

How to Use the Capacitance Converter

1. Enter the known capacitance value.

2. Select its current unit, such as µF, nF, or pF.

3. Select the desired output unit.

4. Calculate and review the converted value.

5. When decoding a printed code, confirm that the component uses the expected pF code convention.

Unit symbols are case-sensitive. Use F for farad, mF for millifarad, µF for microfarad, nF for nanofarad, and pF for picofarad. When the micro symbol is unavailable, uF is often used informally in plain text, but µF is the SI-prefix form.

What Is Capacitance?

Capacitance describes the ratio of electric charge stored on a conductor to the potential difference associated with that charge. For an ideal capacitor:

C = Q/V

where C is capacitance, Q is electric charge, and V is voltage. The SI unit of capacitance is the farad, symbol F. One farad equals one coulomb per volt:

1 F = 1 C/V

In electronics, one farad is relatively large, so capacitor values are commonly stated in millifarads, microfarads, nanofarads, or picofarads.

Capacitance Units and SI Prefixes

Common Capacitance Relationships

• 1 F = 1,000 mF

• 1 F = 1,000,000 µF

• 1 F = 1,000,000,000 nF

• 1 F = 1,000,000,000,000 pF

• 1 mF = 1,000 µF

• 1 µF = 1,000 nF = 1,000,000 pF

• 1 nF = 1,000 pF

Capacitance Conversion Formula

Express each unit as a factor of one farad, then use:

Target value = Source value × Source factor in F ÷ Target factor in F

Example: Convert 4.7 µF to nF and pF

4.7 µF × 1,000 = 4,700 nF

4.7 µF × 1,000,000 = 4,700,000 pF

Example: Convert 220 nF to µF

220 nF ÷ 1,000 = 0.22 µF

Example: Convert 3,300 pF to nF and µF

3,300 pF ÷ 1,000 = 3.3 nF

3,300 pF ÷ 1,000,000 = 0.0033 µF

Capacitance Conversion Chart

How to Read a Three-Digit Capacitor Code

In the common three-digit convention, capacitance is expressed in picofarads. The first two digits are the significant figures and the third digit is the number of zeros that follow:

Capacitance in pF = First two digits × 10^{Third digit}

For example, code 104 means 10 × 10⁴ pF = 100,000 pF = 100 nF = 0.1 µF.

Three-Digit Capacitor Code Examples

Special and Manufacturer-Specific Markings

Not every marking follows the basic three-digit rule. Some capacitor families use a letter as a decimal marker, while some low-picofarad coding systems use 9 to indicate division by ten. For example, a manufacturer may document 919 as 9.1 pF. These special cases are not universal.

A code such as 4R7 may be used by some manufacturers to represent 4.7 pF, but the same characters can have another meaning in a different component system. Very small surface-mount capacitors may have no body marking at all. Always consult the relevant series datasheet, packaging label, bill of materials, or measured value.

Capacitance Tolerance Letters

A letter following the capacitance code may indicate tolerance. Common examples include:

These examples are widely used, but the full marking system still depends on the capacitor family. Other letters may describe temperature characteristic, rated voltage, failure rate, or production information rather than capacitance tolerance.

Do Not Confuse Capacitor and Resistor Codes

A three-digit code can look identical on resistors and capacitors while using a different base unit. For example, 104 on a capacitor following the pF convention means 100,000 pF or 0.1 µF. On a resistor using the common ohm convention, 104 means 100,000 Ω or 100 kΩ. Identify the component type before decoding the number.

Capacitance in Circuit Calculations

Convert capacitance to farads before using it in SI-based equations unless the equation explicitly uses another unit.

Worked Circuit Example

A capacitor is marked 104 and is connected in an ideal RC circuit with a 10 kΩ resistor.

1. Decode 104 as 100,000 pF.

2. Convert 100,000 pF to 100 nF or 0.1 µF.

3. Convert 0.1 µF to 0.0000001 F.

4. Calculate τ = RC = 10,000 Ω × 0.0000001 F = 0.001 s.

The ideal RC time constant is 1 ms.

Accuracy and Practical Limits

• Unit conversion is exact when the original number is exact, but a real capacitor has tolerance.

• Capacitance can vary with temperature, frequency, DC bias, aging, and measurement conditions depending on capacitor technology.

• Parasitic resistance and inductance affect real behavior, especially at high frequency.

• A body code may be incomplete or manufacturer-specific.

• Use a suitable capacitance meter and the manufacturer's test conditions when actual value matters.

• Do not infer voltage rating, polarity, dielectric, or safety classification from capacitance alone.

Common Capacitance Conversion Mistakes

• Using C = Q × V instead of C = Q/V.

• Using C as the unit symbol for capacitance instead of F.

• Confusing mF with µF; 1 mF equals 1,000 µF.

• Moving the decimal point in the wrong direction between µF, nF, and pF.

• Reading 104 as 104 pF instead of 100,000 pF under the standard three-digit convention.

• Applying capacitor pF decoding to a resistor marking.

• Assuming every printed letter is a tolerance code.

• Using a nominal converted value as if it were a measured capacitance.

Capacitance Conversion FAQ

How many nanofarads are in one microfarad?

One microfarad equals 1,000 nanofarads.

How many picofarads are in one nanofarad?

One nanofarad equals 1,000 picofarads.

What does capacitor code 104 mean?

Under the common pF code convention, 104 means 10 followed by four zeros in picofarads: 100,000 pF = 100 nF = 0.1 µF.

What does capacitor code 472 mean?

Under the common pF code convention, 472 means 47 × 10² pF = 4,700 pF = 4.7 nF.

Is uF the same as µF?

In informal electronic text, uF is often substituted when the micro symbol is unavailable. Both are intended to represent microfarads, but µF is the proper SI-prefix symbol.

Can a capacitance code identify the voltage rating?

Not by itself. A capacitance code identifies capacitance only under its documented convention. Voltage rating and other properties require the complete manufacturer marking or datasheet.

Why can two capacitors with the same marked value measure differently?

Manufacturing tolerance and operating conditions can change the measured capacitance. The amount depends on capacitor technology, temperature, frequency, applied DC bias, aging, and the specified test method.

Capacitance Conversion Video

Watch the original capacitance conversion video on YouTube.

References

• NIST Guide to the SI: Farad and SI Prefixes

• NIST Metric Prefixes

• KEMET Capacitor Datasheet: Capacitance and Tolerance Codes

• KEMET MIL-PRF-20 Capacitor Marking Guide