How It Works

The calculator uses Ohm's Law to determine voltage from current and resistance. Multiply the current flowing through the resistor by its resistance to obtain the voltage across the resistor.

V = I × R, where V is voltage in volts (V), I is current in amperes (A), and R is resistance in ohms (Ω).

Example

For example, a current of 3 A flowing through a resistance of 4 Ω produces a voltage of 12 V because V = 3 × 4 = 12 V.

Frequently Asked Questions

What is the formula for voltage?

Using Ohm's Law, voltage is calculated with V = I × R, where I is current in amperes and R is resistance in ohms.

How do you calculate voltage from current and resistance?

Multiply the current in amperes by the resistance in ohms. For example, 3 A × 4 Ω = 12 V.

What unit is voltage measured in?

Voltage is measured in volts (V). One volt is equivalent to one joule per coulomb.

What is Ohm's Law?

Ohm's Law describes the relationship between voltage, current, and resistance in an electrical circuit. It can be written as V = IR.

What voltage is produced by 3 amps through 4 ohms?

The voltage is 12 volts. Using V = IR, the calculation is 3 A × 4 Ω = 12 V.

Can voltage be calculated if current and resistance are known?

Yes. When current and resistance are known, voltage can be calculated directly using V = I × R.