About The Capacitor Charge and Discharge Calculator

The Capacitor Charge and Discharge Calculator estimates capacitor voltage at a selected time for a simple RC charge or discharge curve.

How to Use the Capacitor Calculator Online

1. Select charge or discharge mode.
2. Enter supply voltage, resistance, capacitance, capacitance unit, and elapsed time.
3. Run the calculator to see capacitor voltage and time constant.

Choosing Options Correctly

This assumes an ideal single-resistor/single-capacitor network. Real capacitors have tolerance, leakage, ESR, dielectric behavior, and circuit loading that can change timing.

Common Use Cases

• Estimate reset, delay, or filter transient timing.
• Check capacitor voltage at a specific time point.
• Compare charge and discharge behavior for RC values.

Quick FAQ

Does discharge use the supply voltage field?
Use the initial capacitor voltage as the starting voltage for a discharge estimate, then enter the resistance and time of interest.

Should I verify this on hardware?
Yes. Capacitor tolerance, leakage, ESR, source resistance, and the circuit threshold can move the real waveform.

Does it model electrolytic capacitor behavior?
Only ideally. Electrolytics can have wide tolerance, leakage, temperature effects, and aging that are not included.

Can it predict energy safely?
Use calculated energy carefully and include voltage rating, discharge paths, insulation, and safe handling for high-energy capacitors.