Capacitor Energy
Calculator
Results
- Stored energy
- 0.072
- Stored charge
- 0.012
Physics results
| Stored energy | 0.072 |
| Stored charge | 0.012 |
formula-map diagram
- Stored energy
- 0.072
- Stored charge
- 0.012
Physical relationship
Formula
E = ½ × C × V²= 0.072
Note
This result applies an idealized textbook equation to the numbers you entered; it ignores air resistance, material tolerances and other real-world losses.
More in Physics and engineering
See all →Frequently asked questions
What energy does a capacitor actually store?+
A capacitor stores energy in the electric field created between its two charged plates, calculated as E = ½CV², where C is capacitance in farads and V is the voltage across it. This energy can be released quickly, which is why capacitors are used in applications like camera flashes.
Why does energy scale with the square of voltage, not linearly?+
As voltage increases, both the amount of stored charge and the voltage itself increase together, and since energy depends on the product of charge and voltage, doubling the voltage actually quadruples the stored energy. This is a common surprise for anyone expecting a simple proportional relationship.
How is capacitor energy different from a capacitor's charge?+
Charge (Q = CV) measures how much electrical charge is stored on the plates and scales linearly with voltage, while energy scales with voltage squared. A capacitor can hold twice the charge at twice the voltage, but it stores four times the energy.
Why is capacitor energy storage described as unsafe even at low voltage?+
Even a modestly sized capacitor charged to a household-level voltage can discharge its entire stored energy in a fraction of a second, producing a current spike large enough to cause a painful shock or damage sensitive electronics. This is why capacitors in appliances like microwaves are specifically flagged as a shock hazard even when unplugged.
What units should capacitance and voltage be in for the result to make sense?+
Capacitance is typically entered in farads (though most real capacitors are rated in microfarads, µF, or picofarads, pF, requiring conversion) and voltage in volts; the result comes out in joules. Forgetting to convert µF to F is the most common source of results being off by a factor of a million.