Amps to Watts Conversion Chart

Comprehensive Amps to Watts Conversion Charts

Use these quick reference tables to convert amps to watts across the most common electrical voltages used worldwide. These charts assume a power factor of 1.0 (resistive load). For inductive loads, remember to multiply the chart wattage by the equipment’s power factor.

12V DC (Automotive, RV, Solar)

12-volt systems are standard for cars, boats, and small off-grid setups.

Current (Amps)	Power (Watts)	Common Application
1A	12W	LED dome light
5A	60W	Small water pump
10A	120W	12V refrigerator
15A	180W	Standard accessory outlet
20A	240W	Light bar
30A	360W	Small power inverter
50A	600W	Winch or large inverter

120V AC (Standard US Household)

120-volt circuits are used for standard wall outlets in North America.

Current (Amps)	Power (Watts)	Common Application
1A	120W	Television
5A	600W	Small blender
10A	1200W	Microwave or small heater
12A	1440W	Max continuous load on 15A breaker
15A	1800W	Max peak load on 15A breaker
16A	1920W	Max continuous load on 20A breaker
20A	2400W	Max peak load on 20A breaker

240V AC (US Heavy Appliances & Global Standard)

240-volt circuits power heavy US appliances (dryers, EV chargers, HVAC) and are the standard wall outlet voltage in many countries.

Current (Amps)	Power (Watts)	Common Application
10A	2400W	Baseboard heater
16A	3840W	Level 2 EV Charger (Standard)
20A	4800W	Water heater
30A	7200W	Clothes dryer
40A	9600W	Electric range / oven
50A	12000W	Large central air conditioner

480V AC Three-Phase (Industrial)

480-volt 3-phase power is standard in US manufacturing and commercial facilities. (Calculated with line-to-line formula, PF 1.0)

Current (Amps)	Power (Watts)	Kilowatts (kW)
10A	8,314W	8.3 kW
20A	16,627W	16.6 kW
50A	41,568W	41.5 kW
100A	83,138W	83.1 kW

Apply This Knowledge

Start with the main conversion tool

Use these calculator pages to apply the concept to real current, voltage, watts, and power-factor problems.Amps to Watts Calculator

Methodology, Review Notes, and Sources

How this calculator works

The calculator applies Watt’s law for DC and resistive loads, then
adds power factor for AC loads and the 1.732 multiplier for balanced
three-phase line-to-line calculations.

DC and resistive loads: W = A x V
Single-phase AC: W = A x V x PF
Three-phase AC: W = 1.732 x A x V x PF

Editorial review

Last reviewed: June 26, 2026. Ampstowatt.com is built around the amps to watts
conversion — our core specialty. Content is maintained by the Ampstowatt
editorial team and checked for formula consistency, unit labels, calculator
behavior, and safety wording.

The page is an educational planning reference, not a licensed
electrical design or inspection service.

Reference sources

FAQ

Frequently Asked Questions

Fast answers for the amps to watts formula, common conversions, and safe planning limits.

W How do I convert amps to watts?

Multiply amps by volts to get watts. For example, 10 amps at 120 volts equals 1,200 watts (10 × 120 = 1,200). For AC circuits with motors or compressors, also multiply by the power factor from the equipment nameplate.

AC What is the formula for amps to watts?

There are three formulas depending on the circuit type. DC: Watts = Amps × Volts. AC single-phase: Watts = Amps × Volts × Power Factor. AC three-phase (line-to-line): Watts = 1.732 × Amps × Volts × Power Factor. For three-phase line-to-neutral: Watts = 3 × Amps × Volts × Power Factor.

1A How many watts are in 1 amp?

1 amp equals a different number of watts depending on the voltage. At 12V, 1 amp = 12 watts. At 120V, 1 amp = 120 watts. At 240V, 1 amp = 240 watts. This assumes power factor of 1.00. For AC motor loads with lower power factor, the real watts will be lower.

V Do I need voltage to convert amps to watts?

Yes — you cannot convert amps to watts without knowing the voltage. Amps measure current flow, and watts measure power. The relationship is Watts = Amps × Volts. Without voltage, there is no way to determine how much power the current represents. A 10-amp load could be 120 watts (at 12V) or 2,400 watts (at 240V).

PF Why does AC amps to watts need power factor?

Power factor (PF) measures how efficiently a device uses current. Resistive loads like heaters use all the current for real work (PF = 1.0). Motors and compressors draw extra current due to inductance, so their power factor is lower (0.70–0.95). Without accounting for PF, you would overestimate watts by 10–40% for these loads.

VS What is the difference between amps and watts?

Amps (amperes) measure the flow rate of electric current — how much charge passes a point per second. Watts measure electric power — the rate at which electrical energy is used or converted to heat, light, or motion. You need both amps and volts to calculate watts: Watts = Amps × Volts.

3P How do I convert three-phase amps to watts?

For three-phase with line-to-line voltage: Watts = √3 × Amps × Volts × Power Factor (√3 ≈ 1.732). For line-to-neutral voltage: Watts = 3 × Amps × Volts × PF. Example: 10A at 480V with PF 0.90 using line-to-line voltage = 1.732 × 10 × 480 × 0.90 = 7,478 watts.

Wh Is watts the same as watt-hours?

No. Watts (W) measure instantaneous power — how fast energy is being used right now. Watt-hours (Wh) measure total energy consumed over time. A 100-watt light bulb running for 3 hours uses 300 watt-hours (0.3 kWh). Your electricity bill charges per kilowatt-hour, not per watt.

APP Can I use this calculator for appliances?

Yes. Enter the amperage from the appliance nameplate, the outlet voltage (120V or 240V in the US), and power factor if listed. For resistive appliances (heaters, toasters, hair dryers), use PF = 1.0. For motor-driven appliances (refrigerators, AC units, washing machines), use the nameplate PF or estimate 0.85.

SA Can I use this calculator for breaker or wire sizing?

You can use the result for load planning, but not for final breaker or wire sizing. The NEC requires that continuous loads (3+ hours) stay at or below 80% of the breaker rating. Final sizing must account for wire gauge, ambient temperature, conduit fill, voltage drop, and local code. Always consult a licensed electrician for safety-critical work.