Calculators
Electric Calculator

Volts to Amps Calculator

Convert voltage (V) to current (A) using watts (I = P/V) or Ohm's Law (I = V/R). Select calculation mode.

Calculate

How to Convert Volts to Amps

Converting voltage (V) to current in amperes (A) is a fundamental electrical calculation. You can do it in two ways: (1) Volts to amps with watts: if you know power P in watts and voltage V, use I = P / V. (2) Volts to amps with ohms: if you know voltage V and resistance R in ohms, use Ohm's Law I = V / R. Both formulas are widely used in circuit design, load sizing, and troubleshooting. Our free Volts to Amps calculator supports both modes — select your calculation, enter the values, and get instant results.

With watts: I = P / V. Example: 2300 W at 230 V gives I = 2300 / 230 = 10 A. With ohms: I = V / R (Ohm's Law). Example: 12 V across 24 Ω gives I = 12 / 24 = 0.5 A. Current is the flow of electric charge; voltage is the potential difference that drives it. Resistance opposes current. In resistive DC or AC (magnitude) circuits, these three quantities are related by V = I × R, so I = V / R when you know V and R.

Use volts-to-amps with watts when you have a device's power rating (e.g. 100 W bulb at 230 V) and want to know the current draw. Use volts-to-amps with ohms when you know the voltage across a resistor and its resistance, or when designing LED circuits, heating elements, or series/parallel resistive loads. Both methods help size fuses, wires, and power supplies, and are essential for safe electrical design.

Our calculator lets you choose "Volts to amps with watts" or "Volts to amps with ohms." Enter voltage (and either watts or ohms), then calculate. Results are in amperes (A). No sign-up required. Whether you're a student, technician, or engineer, the Volts to Amps calculator delivers accurate current values for your electrical calculations.

Example:

With watts: 230 V, 1150 W → I = 1150 / 230 = 5 A. 120 V, 1440 W → I = 12 A. With ohms: 24 V, 48 Ω → I = 24 / 48 = 0.5 A. 230 V, 46 Ω → I = 5 A. A 60 W lamp at 120 V draws 60 / 120 = 0.5 A. A 12 V battery across 6 Ω draws 12 / 6 = 2 A.

Frequently Asked Questions

I = P / V, where I is current in amperes, P is power in watts, and V is voltage in volts. Divide power by voltage to get current. Example: 2300 W at 230 V → I = 10 A.
I = V / R (Ohm's Law). I is current in amperes, V is voltage in volts, R is resistance in ohms. Divide voltage by resistance to get current. Example: 12 V across 24 Ω → I = 0.5 A.
Use watts when you know the power (e.g. appliance rating) and voltage. Use ohms when you know the voltage across a resistive load and its resistance, e.g. resistors, heating elements, or simple DC circuits.
I = V / R applies to resistive AC circuits when using the magnitudes of voltage, current, and resistance. For reactive components (inductors, capacitors), use impedance Z: I = V / Z.
Yes. The Volts to Amps calculator is free. No registration required. Choose watts or ohms mode, enter voltage and watts or ohms, and get current in amperes instantly.