How do I calculate the energy stored in a capacitor?

Use the formula E = 0.5 * C * V^2, where E is energy in joules, C is capacitance in farads, and V is voltage in volts. Enter your capacitance and voltage values into the calculator to get the result instantly.

What units does the capacitor energy calculator use?

The calculator accepts capacitance in farads (F) and voltage in volts (V). The energy result is given in joules (J). Ensure your inputs are in these units for accurate calculations.

Can I use this calculator for capacitors in series or parallel?

This calculator is designed for a single capacitor. For multiple capacitors, first determine the equivalent capacitance of your configuration, then use that value as the capacitance input.

Physics

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Capacitor Energy Calculator.

Calculate energy stored in a capacitor at a given voltage.

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Set your values

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02 / ANSWER

Capacitance

Voltage

energyJ

0.00001J

Results update automatically as you type.

FAQs

What does the capacitor energy calculator assume?

Calculate energy stored in a capacitor at a given voltage. The result is an educational calculation using the stated idealized model; verify engineering or experimental decisions against applicable standards.

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Cite this calculator

Canonical URL: https://mathify.one/en/physics/capacitor-energy

Cite as: Mathify. (n.d.). Capacitor Energy Calculator. https://mathify.one/en/physics/capacitor-energy

Use Cases

Designing power supply circuits

Determine the energy storage capacity of capacitors used in power supplies to ensure they can deliver required energy during voltage dips or power interruptions.

Example: Calculate energy stored in a 1000 µF capacitor charged to 12 V.

Educational physics experiments

Verify theoretical energy calculations in classroom labs or homework problems involving capacitor charging and discharging.

Example: Find the energy stored in a 10 µF capacitor at 50 V.

Frequently Asked Questions

How do I calculate the energy stored in a capacitor?: Use the formula E = 0.5 * C * V^2, where E is energy in joules, C is capacitance in farads, and V is voltage in volts. Enter your capacitance and voltage values into the calculator to get the result instantly.
What units does the capacitor energy calculator use?: The calculator accepts capacitance in farads (F) and voltage in volts (V). The energy result is given in joules (J). Ensure your inputs are in these units for accurate calculations.
Can I use this calculator for capacitors in series or parallel?: This calculator is designed for a single capacitor. For multiple capacitors, first determine the equivalent capacitance of your configuration, then use that value as the capacitance input.

Tips & Common Mistakes

Tips

Always convert capacitance to farads (F) before entering. For example, 1 µF = 1e-6 F.
Double-check voltage units: use volts (V), not millivolts or kilovolts, unless you convert accordingly.
Remember that energy scales with the square of voltage, so doubling the voltage quadruples the stored energy.
Use the result to compare capacitors for energy storage applications, but consider real-world losses.

Common Mistakes to Avoid

Forgetting to convert microfarads (µF) to farads (F) – this leads to results off by a factor of 10^6.
Using peak voltage instead of the actual voltage across the capacitor, which may be lower due to internal resistance or discharge.
Confusing energy (joules) with power (watts) – this calculator gives energy, not power.

Last updated: August 13, 2026