Watt to Amp Calculator

Convert power in watts to current in amperes with step-by-step calculations.

Power to Current Converter

Common Watt to Amp Conversions

Click on these links to see instant conversions with common values:

Understanding Watt to Amp Conversion

Converting watts to amps requires knowing the voltage of the circuit. For AC circuits, the power factor also plays a crucial role.

Conversion Formulas

For DC Circuits:
Amps (I) = Watts (P) / Volts (V)

For AC Single-Phase Circuits:
Amps (I) = Watts (P) / (Volts (V) × Power Factor (PF))

For AC Three-Phase Circuits:
Amps (I) = Watts (P) / (√3 × Volts (V) × Power Factor (PF))

Where:
• P = Power in Watts
• V = Voltage in Volts
• I = Current in Amperes
• PF = Power Factor (between 0 and 1)
• √3 ≈ 1.732

Key Concepts

  • Watt (W): The unit of real power, representing the rate at which electrical energy is consumed or produced.
  • Ampere (A): The unit of electric current, representing the flow of electric charge.
  • Volt (V): The unit of electric potential difference.
  • Power Factor (PF): In AC circuits, the ratio of real power to apparent power. It indicates how effectively electrical power is being converted into useful work output.

Typical Power Ratings and Amperage

Device Power (Watts) Voltage (Volts) Approx. Amps
LED Light Bulb101200.08
Laptop Charger601200.5
Microwave Oven10001208.33
Hair Dryer180012015
Electric Kettle22002409.17
Electric Shower700024029.17

Frequently Asked Questions

What is the difference between watts and amps?

Watts measure power (how much energy is being used), while amps measure current (how much electricity is flowing). They are related by voltage and, in AC circuits, by power factor.

Why do I need voltage to convert watts to amps?

Power (watts) is the product of voltage and current (and power factor for AC). Without knowing the voltage, you cannot determine the current for a given power.

See Also