Capacitor Energy Calculator
Fill in the values and the answer updates as you type.
How the Capacitor Energy Calculator works
Energy E = ½ × C × V², with C in farads (microfarads × 10⁻⁶). Charge Q = C × V. Energy grows with the square of voltage, so doubling the voltage stores four times the energy. Example: with the default values, stored energy comes to 0.3125 J.
Inputs and results
The Capacitor Energy Calculator takes 2 inputs and gives 3 results.
What you enter
- Capacitance (µF) — starts at 1000.
- Voltage (V) — starts at 25.
What you get
- Stored energy (J)
- Stored energy (mJ)
- Charge (mC)
Example: Capacitor Energy Calculator with the starting values
With capacitance 1000 µF and voltage 25 V, the calculator returns:
| Stored energy (J) | 0.3125 |
|---|---|
| Stored energy (mJ) | 312.5 |
| Charge (mC) | 25 |
Change any value above and the results update straight away.
Capacitor Energy Calculator FAQ
How do I use the Capacitor Energy Calculator?
Enter capacitance and voltage in the fields, then read stored energy (j), stored energy (mj) and charge (mc) in the result panel. The answer updates as you type, and you can press Calculate or Enter to refresh it. Use “Copy link” to share your exact numbers with someone else.
What does the Capacitor Energy Calculator calculate?
Energy and charge stored in a capacitor. It returns stored energy (j), stored energy (mj) and charge (mc) from the 2 values you provide.
What values does the Capacitor Energy Calculator start with?
It opens with capacitance 1000 µF and voltage 25 V so you can see a working result straight away. Replace them with your own numbers, or press Reset to return to these starting values.
Is the Capacitor Energy Calculator free and private?
Yes. It is free, needs no account, and runs in your browser, so nothing you type is sent to or stored on our servers. See the Privacy Policy for details.
Can I rely on the Capacitor Energy Calculator for important decisions?
Treat the result as a well-rounded estimate. Real situations often have details a general calculator cannot know, so confirm important decisions with a qualified professional. See the Disclaimer for more.