Voltage Divider Calculator

Calculate output voltage, resistor values, current, and power dissipation for voltage divider circuits.

Voltage Divider Parameters

Enter values to calculate circuit properties

Solve For

Input Voltage (Vin)

Output Voltage (Vout)

Resistor R1

Resistor R2

Include Load Resistance (Rload)

Load Resistance (Rload)

Current (I)

Voltage Ratio

Power in R1

Power in R2

Enter circuit values and tap Calculate to see results.

Step-by-Step Solution

Voltage Divider Formula

Vout = Vin × R2 / (R1 + R2)

I = Vin / (R1 + R2)

With load: R2eff = R2 || Rload

R2 || Rload: R2 and Rload in parallel
Formula: (R2 × Rload) / (R2 + Rload)

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Pro Tips

Voltage dividers reduce supply voltage — use when you need a reference or sensor bias.

Loading effect: low Rload reduces Vout. Keep Rload >> R2 for accuracy.

Higher resistor values reduce power loss but increase sensitivity to noise.