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Printable Amps to Watts Conversion Chart

By AmpsToWatt Engineering • Updated: June 2026

Whether you're an electrician in the field, a DIY home renovator, or designing an off-grid solar system, having quick access to amperage-to-wattage conversions saves time and prevents dangerous overloads.

Below is a comprehensive, print-friendly cheat sheet covering the most common voltages: 12V (DC/Solar), 120V (Standard US), and 240V (High-Power US). You can print this page directly using your browser's print function (Ctrl+P / Cmd+P) to keep a copy in your toolbox or stick it inside your breaker panel door.

Amps to Watts Cheat Sheet

12V DC (Automotive, Solar, RV)

Formula: Watts = Amps × 12

Current (Amps) Power (Watts)
1 Amp12 W
5 Amps60 W
10 Amps120 W
20 Amps240 W
50 Amps600 W
100 Amps1,200 W

120V AC (Standard US Household)

Formula: Watts = Amps × 120 (Assuming PF=1.0)

Current (Amps) Power (Watts)
1 Amp120 W
5 Amps600 W
10 Amps1,200 W
15 Amps (Standard Breaker)1,800 W
20 Amps (Kitchen Breaker)2,400 W
30 Amps (RV Hookup)3,600 W

240V AC (High-Power Appliances & EVs)

Formula: Watts = Amps × 240 (Assuming PF=1.0)

Current (Amps) Power (Watts)
10 Amps2,400 W
20 Amps4,800 W
30 Amps (Dryer/Water Heater)7,200 W
40 Amps (Oven/Range)9,600 W
50 Amps (EV Charger)12,000 W
100 Amps (Subpanel)24,000 W
Need a different voltage?

Check out our comprehensive interactive Conversion Charts page or use the Calculator Suite to find the exact wattage for any voltage and power factor.

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 amps to watts formula?

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. The DC formula also works for pure resistive AC loads where power factor is 1.00.

1A How many watts is 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.

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.

SA Can I use amps to watts for breaker sizing?

You can use the result for load planning, but not for final breaker sizing. The NEC requires that continuous loads (3+ hours) stay at or below 80% of the breaker rating. A 20A breaker on 120V handles 2,400W maximum, but only 1,920W for continuous loads. Final sizing must account for wire gauge, ambient temperature, conduit fill, and local code.

PF Why does power factor matter in amps to watts conversion?

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.

⇄ How do I convert watts back to amps?

Divide watts by volts: Amps = Watts ÷ Volts. For AC with power factor: Amps = Watts ÷ (Volts × PF). For example, a 1,500W heater on 120V draws 1,500 ÷ 120 = 12.5 amps. This is useful for checking if an appliance will trip a breaker.

V Is the amps to watts formula different for 120V and 240V?

The formula is the same (Watts = Amps × Volts × PF), but the voltage value changes. At 240V, the same amperage produces twice the wattage as 120V. This is why high-power appliances like dryers and EV chargers use 240V circuits — they get more power without increasing wire size.