Capacitor Calculator

Five capacitor tools in one: decode a 3-digit capacitor code in either direction, solve the charge formula Q = C × V, check a tolerance range, combine capacitors in series or parallel, and find the energy stored in a capacitor. Every mode shows the formula used, and a printable output is included for job-site or coursework documentation.

Use Code Decoder to convert a 3-digit capacitor code to a capacitance value or back again.

Formula: pF = (first two digits) × 10^(third digit). The optional tolerance letter narrows the real-world range.

3-Digit Code — e.g. 104, 473, 222

Tolerance Letter — optional

Capacitance

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Nanofarads

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Microfarads

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µF

Tolerance Range

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Formula: —

Results are for reference and educational purposes only. Verify all values against manufacturer datasheets or a multimeter before use in any circuit design or repair. See full disclaimer below.

How to Use the Capacitor Calculator

Choose a Calculation Mode

Pick Code Decoder, Charge (Q=CV), Tolerance, Series & Parallel, or Energy Stored depending on what you need to solve.

Enter Your Known Values

Type the values you already know and pick the correct unit from each dropdown. Most modes only need two of the three related values.

Click Calculate

Press Calculate to solve for the missing value. Each result shows the formula used and a step-by-step breakdown.

Review and Print

Check the results, tolerance range, or equivalent capacitance, then use Print to capture the results exactly as they appear on screen.

Quick Reference — Common Capacitor Codes

Frequently seen 3-digit capacitor codes on ceramic and film capacitors, with their decoded values.

Code	pF	nF	µF
101	100 pF	0.1 nF	0.0001 µF
102	1,000 pF	1 nF	0.001 µF
103	10,000 pF	10 nF	0.01 µF
104	100,000 pF	100 nF	0.1 µF
105	1,000,000 pF	1,000 nF	1 µF
220	22 pF	0.022 nF	0.000022 µF
330	33 pF	0.033 nF	0.000033 µF
473	47,000 pF	47 nF	0.047 µF
474	470,000 pF	470 nF	0.47 µF

Frequently Asked Questions

What does a 3-digit capacitor code mean?

The first two digits are significant figures and the third digit is a multiplier — the number of zeros to add — with the result given in picofarads (pF). For example, code 104 means 10 followed by four zeros, or 100,000 pF, which equals 100 nF or 0.1 µF.

How do I convert between pF, nF, and µF?

Divide picofarads by 1,000 to get nanofarads, and divide nanofarads by 1,000 to get microfarads. So 100,000 pF equals 100 nF, which equals 0.1 µF. The Code Decoder and Charge tabs convert between units automatically.

What is the difference between capacitors in series and parallel?

In parallel, total capacitance is the sum of all individual values, so it always increases. In series, total capacitance is found using reciprocals, so it is always smaller than the smallest individual capacitor. Series wiring is used when a higher voltage rating or a smaller equivalent value is needed.

What does capacitor tolerance mean and how do I read the letter code?

Tolerance is how far a capacitor's actual value can differ from its labeled value. Common letter codes include J (±5%), K (±10%), and M (±20%), while B, C, and D give a fixed picofarad tolerance for very small capacitors. The letter Z is asymmetric — +80% and −20% — meaning the part can run well above its label but only slightly below it.

How do I calculate the energy stored in a capacitor?

Energy stored is found with E = ½ × C × V², where C is capacitance in farads and V is voltage in volts, giving the result in joules. A larger capacitance or a higher voltage both increase the stored energy, and voltage has the larger effect since it is squared.