Electrical

Capacitor Discharging Voltage Calculator

Find remaining capacitor voltage during resistive discharge.

Ideal component relationshipsUnits and assumptions explained below
Circuit workbench
Circuit workbench

Keep RMS, peak and DC values distinct.

See the method

Enter circuit values

Runs on your device

Your circuit result

Your result

Let’s calculate.

Use the Calculate button to see your result.

Review the method below for assumptions and conventions.

How to use this tool

  1. Enter voltage, resistance, capacitance, elapsed time.
  2. Select Calculate to view the result.
  3. Check the method and assumptions below before using the result.

Input reference and sample values

Use the units and choices shown for each field. Sample values are provided for practice, not as recommendations.

InputFormat and unitsSample
VoltageNumeric value. Unit: V. Zero or positive.12
ResistanceNumeric value. Unit: Ω. Must be greater than zero.100
CapacitanceNumeric value. Unit: F. Must be greater than zero.0.0001
Elapsed timeNumeric value. Unit: s. Zero or positive.0.01

Result for these sample inputs

4.41455329 V

Select Try the example in the form to load these values and calculate them again. This replaces the current form inputs. Compare the result with the method and worked explanation below.

The method, explained

Voltage = initial voltage × exp(−time/(RC)).

A WORKED EXAMPLE

Using voltage = 12 V, resistance = 100 Ω, capacitance = 0.0001 F, elapsed time = 0.01 s, the result is 4.41455329 V. Change these example inputs to match your task; use the method above to check each step.

What to keep in mind

Ideal-component calculation for study and estimation. It does not select safe wiring, protective devices or component ratings for an installation.

Methodology maintained by ClarityKit. How these tools are built and checked.