Watts to Amps Calculator
Convert electrical power in watts to current in amps.
Results update as you type.
How it works
Converting electrical power to current is a common task in wiring, appliance sizing, and electronics, and this calculator does it for direct-current or simple resistive cases. You enter the power in watts and the voltage in volts, and it returns the current in amps. The relationship comes from the fundamental power equation: power equals voltage times current, so current is power divided by voltage. This tells you how much current an appliance draws, which is essential for choosing the right wire gauge, circuit breaker, or fuse, since these are rated by current. For example, a 1,200-watt device on a 120-volt supply draws 10 amps, which fits within a typical household circuit. A key insight is that for the same power, raising the voltage lowers the current, which is exactly why electric utilities transmit power at very high voltages: less current means thinner wires and far smaller energy losses to resistance. For alternating-current circuits with motors or other reactive loads, the true relationship includes a power factor, so this simple conversion applies exactly to direct current and resistive loads and gives a close estimate otherwise. Knowing the current draw helps ensure circuits are not overloaded, a matter of both function and safety. Enter the power and voltage to compute the current in amps.
I = P / V
Current in amps equals power in watts divided by voltage in volts. This comes from the power equation, which states that power equals voltage times current. Rearranging it isolates current. For a fixed power, a higher voltage means a lower current, which is why power is transmitted at high voltage to reduce current and losses.
Source:Electrical engineering
We review all our tools from time to time to ensure accuracy.
Worked example
How to use this calculator
- 1
Enter your values
Enter power and voltage.
- 2
Adjust the options
Fine-tune any options to match your situation.
- 3
Read your result
Current updates instantly as you type — no button to press.
Frequently asked questions
How do you convert watts to amps?
Divide the power in watts by the voltage in volts. A 1,200-watt appliance on 120 volts draws 10 amps. The calculator does this instantly. This applies exactly to direct current and resistive loads; alternating-current circuits with motors also involve a power factor that this simple formula does not include.
Why divide watts by volts?
Electrical power equals voltage times current, so to find the current you rearrange the equation and divide the power by the voltage. This is a direct consequence of how power, voltage, and current relate. Knowing any two of the three lets you find the third using this same power equation.
Why does higher voltage mean lower current?
For a fixed amount of power, current and voltage trade off, since their product is the power. Raising the voltage lets the same power flow with less current. Utilities exploit this by transmitting electricity at very high voltage, reducing current and the energy lost to wire resistance, which depends on the current squared.
Why does knowing the current matter?
Wires, circuit breakers, and fuses are rated by the current they can safely carry. Knowing an appliance's current draw lets you choose the right wire gauge and protection and avoid overloading a circuit, which can trip breakers or cause overheating and fire. It is essential for safe electrical installation and appliance use.
Does this work for AC circuits?
The simple formula works exactly for direct current and purely resistive alternating-current loads like heaters and incandescent bulbs. For AC circuits with motors, transformers, or other reactive loads, the real relationship includes a power factor, so the actual current can be higher than this estimate. For those, multiply by the power factor.