Amps to Watts Calculator

Q: How do I convert amps to watts?

To convert amps to watts, divide the power in watts by the voltage in volts. For DC circuits: Amps = Watts ÷ Volts. For AC single-phase circuits, also divide by the power factor: Amps = Watts ÷ (Volts × Power Factor). For AC three-phase circuits: Amps = Watts ÷ (Volts × Power Factor × √3). Use our calculator above to get an instant result.

Q: What is the formula for amps to watts?

There are three amps-to-watts formulas depending on circuit type. DC: A = W ÷ V. AC Single-phase: A = W ÷ (V × PF). AC Three-phase: A = W ÷ (V × PF × √3), where √3 ≈ 1.732. PF is the power factor, a value between 0 and 1 that accounts for reactive power in AC circuits. DC circuits always use a power factor of 1.

Q: How many amps is 1500 watts?

It depends on voltage and circuit type. At 120V DC: 1500 ÷ 120 = 12.5 amps. At 240V DC: 1500 ÷ 240 = 6.25 amps. At 120V AC single-phase with a power factor of 0.8: 1500 ÷ (120 × 0.8) = 15.625 amps. At 240V AC single-phase with PF 0.8: 1500 ÷ (240 × 0.8) = 7.8125 amps.

Q: What is the difference between watts and amps?

Current (A) measure electrical power — the rate at which energy is consumed or produced. Amps (A), or amperes, measure electric current — the rate at which electric charge flows through a circuit. The two are linked by voltage: Power (W) = Current (A) × Voltage (V). A device can draw few amps at high voltage or many amps at low voltage while consuming the same wattage.

Built by an electrical engineering student Last updated July 2026 Estimates only — how we check

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Current (A)

Voltage (V)

Circuit Type

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Choose a circuit type and enter values to see the formula used.

How do you convert amps to watts?

Multiply amps by volts. A 15 A load on a 120 V circuit uses 15 × 120 = 1800 watts. For AC single-phase, multiply by the power factor too: W = A × V × PF. So 15 A at 120 V with a power factor of 0.9 gives 15 × 120 × 0.9 = 1620 W.

Amps to Watts Formula

DC Circuits

W = A × V

In a DC circuit, current equals power divided by voltage. There is no reactive power, so no power factor is needed. Example: a 60 W bulb on 12 V draws 60 ÷ 12 = 5 A.

AC Single-phase

W = A × V × PF

AC circuits carry reactive power, so the power factor (PF) scales the real power. A PF of 1.0 is perfectly resistive (heaters, incandescent bulbs); motors and electronics typically range from 0.7 – 0.95.

AC Three-phase

W = A × V × PF × √3

Three-phase power distributes load across three conductors. The √3 factor (≈ 1.732) accounts for the phase angle between conductors. Voltage here is line-to-line (e.g. 400 V in Europe, 208 V or 480 V in the US).

Common Amps to Watts Examples

Watts	Voltage	Result (Amps)
100 W	120 V	0.8333 A
500 W	120 V	4.1667 A
1,000 W	120 V	8.3333 A
1,500 W	120 V	12.5000 A
2,000 W	120 V	16.6667 A
100 W	240 V	0.4167 A
1,000 W	240 V	4.1667 A
1,500 W	120 V	15.6250 A

Reading a Circuit's Amp Draw: Worked Scenarios

Electricians and homeowners often work backwards from a measured current to understand what a circuit is actually doing. Here are three realistic scenarios where knowing amps → watts is immediately practical:

Clamp-meter reading on a kitchen circuit: 12.3 A at 120 V.
Power = 12.3 × 120 = 1,476 W. This suggests a 1,500 W appliance (such as a toaster or coffee maker) is running. The circuit is operating at 82 % of a standard 15 A limit — within code for intermittent loads, but too high for a continuous load per NEC 210.19(A).
240 V dryer drawing 22 A.
Power = 22 × 240 = 5,280 W. A typical electric clothes dryer uses a heating element rated around 4,000–5,000 W plus a small motor, so 5,280 W at peak heat is normal. This confirms a 30 A, 240 V dedicated circuit is correctly sized (circuit not loaded above 80 % on a continuous basis).
Three-phase 208 V industrial panel: phase current 18 A, PF 0.85.
Real power = 18 × 208 × 0.85 × 1.732 ≈ 5,512 W per phase, or about 5.5 kW total (for a balanced single-phase load on that panel leg). This kind of check is routine when commissioning commercial HVAC or lighting panels to verify actual load vs. design load.
Solar inverter output: 6.5 A at 240 V single-phase, PF ≈ 1.0.
Power export = 6.5 × 240 = 1,560 W. Monitoring AC output amps is a quick field check that a grid-tied inverter is producing close to its rated output on a sunny day.

Frequently Asked Questions

How do I convert amps to watts?

Divide the power in watts by the voltage in volts. For DC circuits: A = W ÷ V. For AC single-phase circuits, also divide by the power factor: A = W ÷ (V × PF). For AC three-phase: A = W ÷ (V × PF × √3). Use the calculator at the top of this page to get an instant result.

What is the formula for amps to watts?

There are three formulas depending on circuit type:

DC: A = W ÷ V
AC Single-phase: A = W ÷ (V × PF)
AC Three-phase: A = W ÷ (V × PF × √3), where √3 ≈ 1.732

PF is the power factor — a value between 0 and 1 that accounts for reactive power in AC circuits. DC circuits always have a power factor of 1.

How many amps is 1500 watts?

It depends on voltage and circuit type:

120 V DC: 1500 ÷ 120 = 12.5 A
240 V DC: 1500 ÷ 240 = 6.25 A
120 V AC single-phase (PF 0.8): 1500 ÷ (120 × 0.8) = 15.625 A
240 V AC single-phase (PF 0.8): 1500 ÷ (240 × 0.8) = 7.8125 A

What is the difference between watts and amps?

Current (A) measure electrical power — the rate at which energy is consumed or produced. Amps (A) measure electric current — the rate at which electric charge flows through a conductor. The two are linked by voltage: W = A × V. A device can draw few amps at high voltage or many amps at low voltage while consuming the same wattage. Think of voltage as pressure, amps as flow, and watts as the total power delivered.