Calculating your stored energy is straightforward once you know the Capacitor Energy formula and what each input means. This guide explains the method in plain language, walks through a manual calculation, and gives worked examples you can follow — then you can do it instantly with the Capacitor Energy Calculator.
What is Capacitor Energy?
The Capacitor Energy calculation tells you your stored energy from a few simple inputs. The figure you are solving for here is the stored energy.
The Capacitor Energy formula
The core formula is:
Stored energy = 0.5 × (Capacitance ÷ 1000000) × Voltage ^ 2Here is what each input means:
- Capacitance — a value measured in µF. Example: 1,000 µF.
- Voltage — a value measured in V. Example: 12 V.
How to calculate it step by step
- Write down the capacitance (for example, 1,000 µF).
- Write down the voltage (for example, 12 V).
- Apply the formula above to get your stored energy.
- Double-check the result with the Capacitor Energy Calculator.
Worked examples
Example 1
| Input / Output | Value |
|---|---|
| Capacitance | 1,000 µF |
| Voltage | 12 V |
| Stored energy | 0.072000 |
| Charge stored | 0.012000 |
With capacitance of 1,000 µF and voltage of 12 V, the stored energy works out to 0.072000.
Example 2
With capacitance of 2,000 µF and voltage of 12 V, the stored energy works out to 0.144000.
| Result | Value |
|---|---|
| Stored energy | 0.144000 |
| Charge stored | 0.024000 |
Example 3
With capacitance of 500 µF and voltage of 12 V, the stored energy works out to 0.036000.
| Result | Value |
|---|---|
| Stored energy | 0.036000 |
| Charge stored | 0.006000 |
Tips for an accurate result
- Keep your units consistent — mixing, say, months with years or grams with kilograms is the most common source of error.
- Round only at the very end. Rounding inputs early can shift the final answer noticeably.
- Re-run the numbers whenever an input changes, rather than estimating from an old result.
Prefer not to do the maths by hand? — the Capacitor Energy Calculator does it instantly, for free, with the formula and a worked example built in.
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