Capacitor Voltage Divider Calculator

Calculate capacitive voltage divider circuits with impedance, frequency response, and energy storage analysis.
Basic Calculator
Standard Capacitors
Frequency Response
Energy Calculator

Capacitor Voltage Divider Calculator

Capacitive Voltage Divider Formula:
Vout = Vin × C1 / (C1 + C2) Note: C1 is the upper capacitor (opposite to resistor dividers)
Vin = 5V
Vin = 12V
C1 = 100nF, C2 = 470nF
C1 = 1μF, C2 = 10μF
Enter any three values and click Calculate.

Note: The circuit diagram updates automatically as you enter values.

Auto-calculate as you type

Standard Capacitor Finder

Find Standard Capacitors for Your Voltage Divider

Enter input and output voltages to find standard capacitors.
C1 C2 Actual Vout Error (%)

Frequency Response Analysis

Calculate Impedance and Phase Response

Enter capacitor values and frequency for impedance analysis.

Energy Storage Calculator

Calculate Energy Storage in Capacitive Divider

Enter values to calculate energy storage.

Capacitor Voltage Divider Examples & Applications

AC Coupling Example

Given: Vin=10V AC, C1=100nF, C2=470nF

High Voltage Measurement

Given: Vin=1000V, C1=1nF, C2=10nF

RF Attenuator Example

Given: Vin=5V RF, C1=22pF, C2=68pF

Understanding capacitive voltage dividers

A capacitive voltage divider splits an AC voltage using two capacitors in series instead of two resistors. The output taken across the second capacitor follows Vout = Vin × C1 / (C1 + C2). Note the ratio is the opposite intuition from a resistor divider: the output is proportional to the series capacitor C1, because in a series string the smaller capacitor drops the larger share of the voltage.

Why use capacitors instead of resistors

A capacitive divider dissipates almost no power — capacitors store and return energy rather than turning it into heat — so it is the natural choice for high-voltage AC sensing and RF, where a resistive divider would waste power and heat up. It also blocks DC, passing only the AC component. The trade-off is that it only works with AC: the division ratio comes from capacitive reactance (XC = 1/(2πfC)), so it depends on the signal being time-varying.

Loading and frequency

Like its resistive cousin, a capacitive divider must feed a high-impedance load or the ratio shifts. Any load resistance forms a high-pass filter with the capacitors, so the divider behaves ideally only well above that corner frequency. For precise RF work the stray capacitance of the board and the probe must be included in C2.

Where capacitive dividers are used

High-voltage AC measurement and metering, RF impedance matching and antenna tuning networks, the feedback tap of Colpitts and Clapp oscillators, capacitive touch and level sensing, and coupling/attenuating signals without a DC path.

Common questions

Does it work with DC? No — capacitors block DC, so a capacitive divider only divides AC or changing signals. Use a resistive divider for DC.

Why does the smaller capacitor get more voltage? In series, all capacitors carry the same charge (Q); since V = Q/C, the smaller capacitance develops the larger voltage.