Watts to Amps Calculator
Convert watts to amps using voltage. Supports both DC and single-phase AC circuits with power factor.Updated 2026-03-16
Common Appliance Amp Draw (120V)
| Appliance | Watts | Amps @120V | Amps @240V |
|---|---|---|---|
| LED Light Bulb | 10 W | 0.08 A | 0.04 A |
| Laptop Charger | 65 W | 0.54 A | 0.27 A |
| Desktop Computer | 200 W | 1.67 A | 0.83 A |
| Television (55") | 120 W | 1.00 A | 0.50 A |
| Refrigerator | 150 W | 1.25 A | 0.63 A |
| Microwave | 1000 W | 8.33 A | 4.17 A |
| Hair Dryer | 1500 W | 12.50 A | 6.25 A |
| Space Heater | 1500 W | 12.50 A | 6.25 A |
| Toaster Oven | 1200 W | 10.00 A | 5.00 A |
| Vacuum Cleaner | 1400 W | 11.67 A | 5.83 A |
| Washing Machine | 500 W | 4.17 A | 2.08 A |
| Electric Dryer | 5000 W | 41.67 A | 20.83 A |
| Central AC | 3500 W | 29.17 A | 14.58 A |
| Electric Oven | 2500 W | 20.83 A | 10.42 A |
How to Convert Watts to Amps
DC: Amps = Watts ÷ Volts. Simple division of power by voltage.
AC (Single Phase): Amps = Watts ÷ (Volts × Power Factor). The power factor accounts for the phase difference between voltage and current in AC circuits.
Example: A 1500W heater on a 120V circuit draws 12.5 amps (1500 ÷ 120).
⚡ Important: Always ensure your circuit breaker and wiring are rated for the calculated amperage. Standard US outlets are 15A or 20A circuits.
Frequently Asked Questions
How do I convert watts to amps?
Divide watts by volts: Amps = Watts ÷ Volts. For AC circuits, also divide by the power factor: Amps = Watts ÷ (Volts × PF). You need to know the voltage of your circuit (commonly 120V or 240V in the US).
What is power factor and when does it matter?
Power factor (PF) is the ratio of real power to apparent power in AC circuits, ranging from 0 to 1. Resistive loads like heaters and incandescent bulbs have a PF near 1.0. Motors, compressors, and fluorescent lights typically have a PF of 0.7-0.9. For DC circuits, power factor does not apply.
How many watts can a 15-amp circuit handle?
A 15-amp circuit at 120V can handle up to 1,800 watts (15 × 120). However, the NEC recommends loading circuits to no more than 80% capacity for continuous loads, so plan for 1,440 watts max on a 15A circuit.
"Watts to Amps Calculator." ConvKit, conv-kit.com, https://conv-kit.com/tools/watts-to-amps/. Accessed 2026-03-16.