How to use the Capacitor Calculator
- Choose combine, charge & energy, or RC time constant.
- Enter the values (capacitance in µF).
- Read the results.
What does this tool do?
Capacitors combine the opposite way to resistors: in parallel they add, in series their reciprocals add. A capacitor stores charge Q = CV and energy ½CV².
In an RC circuit the time constant τ = RC is the time to charge to about 63%; after 5τ it's effectively full. The same values set the cut-off frequency of an RC filter.
Why use it?
- Three capacitor calculations.
- Cut-off frequency included.
- Microfarad inputs.
The formula
Parallel: C = C₁ + C₂
Series: 1/C = 1/C₁ + 1/C₂
τ = RC, f_c = 1 ÷ 2πRC
Privacy
The calculation happens instantly in your browser. The numbers you enter are not sent to our servers or saved. There's no account to create and nothing to install.
Last reviewed by the M2Toolkit team.