Watts/Amps/Volts Converter
Convert between watts, amps, and volts for DC, single-phase, and three-phase circuits.
Need to calculate electrical power consumption, energy cost, or generator sizing? Try our Power Calculator.
Input
Result
Formula
AC 1Ο: A = W / (V Γ PF)
π‘ Difference from Power Calculator: This tool focuses on converting between W, A, and V for circuit design. The Power Calculator handles energy cost, generator sizing, and power consumption analysis.
Understanding Watts, Amps, and Volts
The relationship between watts, amps, and volts is fundamental to electrical engineering. Whether you're sizing a circuit breaker, selecting a wire gauge, or estimating energy costs, understanding these conversions is essential for safe and efficient electrical work.
Key Formulas
Power Factor Explained
Power factor (PF) is the ratio of real power (watts) to apparent power (volt-amps). A PF of 1.0 means all power is real (purely resistive load like heaters). Motors, transformers, and fluorescent lights have PF below 1.0 (typically 0.7β0.9), meaning they draw more current than a resistive load for the same real power.
How to Convert Watts to Amps
Frequently Asked Questions
How do I convert watts to amps?
Divide watts by volts. For DC: A = W / V. For AC single-phase: A = W / (V Γ PF). For AC three-phase: A = W / (V Γ PF Γ β3). For example, 1500W at 120V DC = 12.5A. At 120V AC with PF=0.85 = 14.7A.
How many amps is 1500 watts at 120V?
For DC: 1500 / 120 = 12.5A. For AC single-phase with PF=0.85: 1500 / (120 Γ 0.85) = 14.7A. The AC circuit draws more current because not all apparent power is real power.
What is power factor?
Power factor is the ratio of real power (watts) to apparent power (volt-amps). It ranges from 0 to 1. PF=1 means purely resistive load (heaters, incandescent lights). PF<1 means reactive load (motors, transformers). Low PF causes higher current draw for the same real power.
How do I convert amps to kW?
First convert amps to watts: DC: W = V Γ A. AC 1Ο: W = V Γ A Γ PF. AC 3Ο: W = V Γ A Γ PF Γ β3. Then divide by 1,000 to get kW. For example, 10A at 240V AC 1Ο with PF=0.85 = 10 Γ 240 Γ 0.85 = 2,040W = 2.04kW.
What is the difference between watts and volt-amps?
Watts measure real power β the energy actually consumed. Volt-amps (VA) measure apparent power β the total power the circuit must carry. For resistive loads (PF=1), W = VA. For reactive loads (PF<1), VA > W. Circuit breakers and wiring must be sized based on VA, not W.