Potential Divider Calculator: Vout = Vin × R2/(R1 + R2)

Potential Divider Calculator

⚡ Electricity & magnetism. Use the Potential divider formula to find output voltage, input voltage, r₁, r₂: pick the value you want, type the others, and the answer updates as you go.

V_{out} = V_{in} \times \dfrac{R_2}{R_1 + R_2}

Output voltage (V)Input voltage (V)R₁ (Ω)R₂ (Ω)

Output voltage4 V

Pick the ○ next to the value you want to find, fill in the others, and it solves as you type.

What each letter means

Quantity	Unit
Output voltage	V
Input voltage	V
R₁	Ω
R₂	Ω

Worked example

Find the output voltage when Input voltage = 12 V, R₁ = 2000 Ω, R₂ = 1000 Ω.

Using Vout = Vin × R2/(R1 + R2): Output voltage = 4 V.

Frequently asked questions

What is the formula for Potential divider?

Vout = Vin × R2/(R1 + R2).

What do the letters stand for, and what units are used?

Output voltage in V, Input voltage in V, R₁ in Ω, R₂ in Ω.

How do you calculate output voltage?

Put the values into Vout = Vin × R2/(R1 + R2). For example, with Input voltage = 12 V, R₁ = 2000 Ω, R₂ = 1000 Ω, output voltage = 4 V.

Can I solve for a different value?

Yes. In the calculator above, pick the circle next to any value (output voltage, input voltage, r₁, r₂) and fill in the others: it rearranges the formula for you.