Watts to amps calculator
Enter a wattage and select the supply voltage. The calculator applies the power formula Amps = Watts ÷ Volts and shows the exact current draw — useful for checking whether an appliance will trip a breaker, sizing an extension lead, or reading your electricity bill.
1,500 W at 230 V = 6.52 A (1.50 kW)
Common appliance wattage and current draw
Typical wattages for household appliances, with the resulting amperage at 120 V (US/CA) and 230 V (UK/AU/NZ). Actual draw varies by model — check the appliance label or spec sheet for the exact figure.
| Appliance | Watts | Amps @ 120 V / 240 V† | Amps @ 230 V |
|---|---|---|---|
| LED light bulb | 9 W | 0.08 A | 0.04 A |
| Phone charger | 18 W | 0.15 A | 0.08 A |
| Laptop charger | 65 W | 0.54 A | 0.28 A |
| Refrigerator | 150 W | 1.25 A | 0.65 A |
| Microwave | 1,000 W | 8.33 A | 4.35 A |
| Toaster | 1,200 W | 10.00 A | 5.22 A |
| Hair dryer / Space heater | 1,500 W | 12.50 A | 6.52 A |
| Electric kettle | 2,200 W | 18.33 A | 9.57 A |
| Dishwasher | 1,800 W | 15.00 A | 7.83 A |
| Clothes dryer (electric) | 5,000 W | 20.83 A† | 21.74 A |
| Electric water heater | 4,500 W | 18.75 A† | 19.57 A |
| Central AC (3-ton) | 3,500 W | 14.58 A† | 15.22 A |
| EV charger (Level 2) | 7,200 W | 30.00 A† | 31.30 A |
† US/CA: requires a dedicated 240 V circuit. Amps shown at 240 V — not 120 V (dividing watts by 120 gives a theoretical figure; these appliances do not operate on 120 V circuits). Values are typical industry figures, not code minimums.
Common questions
- How many amps is 1,500 watts at 120V?
- 1,500 watts at 120 volts draws 1,500 ÷ 120 = 12.5 amps. A hair dryer or small space heater at 1,500 W will use a full 12.5 A of a 15-amp circuit, leaving almost no headroom. The next step up, a 20-amp circuit on 12-gauge wire, gives a little more margin.
- How do you convert watts to amps?
- Divide the wattage by the voltage: Amps = Watts ÷ Volts. This is a rearrangement of the power formula P = V × I (watts = volts × amps). For example, a 1,000 W microwave on a 120 V circuit draws 1,000 ÷ 120 = 8.33 A. On a 230 V supply the same microwave draws 1,000 ÷ 230 = 4.35 A.
- How many amps is 1,000 watts?
- At 120 V: 1,000 ÷ 120 = 8.33 amps. At 240 V: 1,000 ÷ 240 = 4.17 amps. At 230 V: 1,000 ÷ 230 = 4.35 amps. The amperage depends on the supply voltage — enter your voltage in the calculator above for the exact figure.
- What is the formula for watts to amps?
- The formula is I = P ÷ V, where I is current in amps, P is power in watts, and V is voltage in volts. It comes directly from the power law P = V × I. To go the other way — amps to watts — just multiply: P = V × I. For example, 10 A at 120 V = 1,200 W (1.2 kW).
Last reviewed 2026-08
Reference & education only. Not professional, engineering, or code-compliance advice. Estimates are based on published model codes; local amendments and your Authority Having Jurisdiction (AHJ) govern. Always verify against the current adopted code and a licensed professional before doing work.