# Capacitor Calculator

Created by Luciano Mino
Last updated: Jul 10, 2022

Our capacitor calculator will find every missing parameter from a capacitor based on your input.

With this tool, you can obtain a capacitor's code, capacitance, tolerance, charge, and voltage with ease. This calculator essentially works as a:

• Capacitor calculator;
• Capacitor code calculator;
• Capacitor charge calculator; and
• Voltage across capacitor calculator.

Just input any parameter, and our calculator will do the rest!

## What is a capacitor? Capacitor formula

We've talked about all the features within this tool, but they are of no use if we don't know what a capacitor is.

A capacitor is a device that stores energy by means of an electric field. Generally, capacitors use two conductors separated by a dielectric medium, and there are many different capacitor shapes (parallel plates, cylindrical, spherical, etc.).

The capacitor formula expresses the relation between the charge ($Q$) stored within the capacitor, its capacitance ($C$), and the voltage ($V$) used to hold that charge:

$C = \frac{Q}{V}$

Using this formula, we can calculate the voltage across the capacitor if we know its capacitance value and the amount of charge it stores.

## Capacitor codes

We use codes to identify capacitors quickly using two values: their capacitance and voltage rating. Voltage rating tells us the maximum voltage the capacitor can withstand while functioning correctly.

For capacitors with capacitance greater than 100 µF, we can often find their value written directly on it (a 200 µF 25 V capacitor has a capacitance of 200 µF and works with voltages up to 25 V).

However, for lower capacitance values, we use a 3-digit capacitor code to identify it:

• First and second digits tell us the first two significant figures of the capacitance in pF.
• The third digit is a multiplier factor. This number indicates which power of 10 we should use to multiply the first and second digits to get the actual value of the capacitance.

For example, to find the code for a 12 µF capacitor:

1. First, we convert the capacitance to pF and extract the first two significant figures: 12 µF = 12,000,000 pF, therefore, 12.
2. Now, we need to find which power of 10 we should multiply 12 pF by to get 12 µF. Answer: 6 th, since 12 * 10⁶ pF = 12 µF.
3. Finally, the code for this capacitor is: 126.

The reverse is just as simple: if we call the third digit n, we only need to multiply the first two digits of the code by 10ⁿ to get the capacitance in pF.

## Capacitor tolerance

We can usually find a letter next to the three-digit code. This letter indicates the range in which we can find the actual value of the capacitance.

Below, we gathered the most commonly used tolerance codes:

Letter

Capacitance

B

±0.1 pF

C

±0.25 pF

D

±0.5 pF

F

±1%

G

±2%

J

±5%

K

±10%

M

±20%

Z

+80%, -20%

Luciano Mino
Code to capacity converter
Code
Tolerance code
K
Capacity
pF
Capacity to code converter
Capacity
pF
Tolerance capacity
±10%
Code
Capacitor parameters
Capacitance (C)
pF
Voltage (V)
V
Stored charge (Q)
nC
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