Case 1
- Stored charge
- 0.001C
- Voltage
- 10V
0.000100F
Open with these valuesCapacitance Calculator
0.000100F
Result: 0.000100 FCapacitance is charge divided by voltage: one millicoulomb held at 10 V is 0.0001 F, or 100 µF. The farad is an enormous unit — real parts are measured in microfarads, nanofarads and picofarads, so expect a lot of leading zeros here.
Worked examples
Case 2
- Stored charge
- 0.005C
- Voltage
- 250V
0.000020F
Open with these valuesCase 3
- Stored charge
- 0.1C
- Voltage
- 50V
0.002000F
Open with these valuesHow it's calculated
C = Q ÷ V
- StepEnter the charge the capacitor holds, in coulombs.
- StepEnter the voltage measured across its terminals.
- StepDivide; the result is the capacitance in farads.
- ResultMultiply by one million to read it in microfarads.
Reference table
| Charge, voltage | Same value in µF | Capacitance |
|---|---|---|
| 0.005, 250 | 20 µF | 0.00002 |
| 0.001, 10 | 100 µF | 0.0001 |
| 0.001, 5 | 200 µF | 0.0002 |
| 0.1, 50 | 2000 µF | 0.002 |
Questions
What is capacitance?
The charge a component holds per volt applied to it. One farad means one coulomb of charge for every volt.
Why is the answer such a small number?
Because the farad is far larger than anything you will hold in your hand. A typical smoothing capacitor is 0.001 F, which everyone writes as 1000 µF instead.
How do I convert farads to microfarads?
Multiply by one million. 0.0001 F is 100 µF, and 0.000000001 F is one nanofarad.
Does capacitance change with the voltage?
For an ideal capacitor, no — more voltage simply stores proportionally more charge. Real ceramic parts do lose capacitance under a DC bias, and electrolytics drift with age and temperature.
Sources and last check
Information, not professional advice.