swap_horiz Looking to convert 18A at 120V back to watts?

How Many Amps Is 2,160 Watts at 120V?

2,160 watts equals 18 amps at 120V on an AC single-phase resistive circuit (PF 1.0). AC resistive at PF 1.0 and the DC baseline land on the same number at this voltage.

At 18A, the NEC 210.19(A) continuous-load sizing math (125% of the load, equivalently 80% of the breaker rating) points to a 25A breaker as the smallest standard size that covers this load continuously. A 20A breaker is the smallest standard size the raw current fits under, but it is non-continuous-only at this load.

2,160 watts at 120V

18 Amps

2,160 watts equals 18 amps at 120 volts (AC single-phase, PF 1.0 resistive)

DC18 A

Try: 2,200W at 120V 2,000W at 120V 2,400W at 120V 1,900W at 120V

Watts

Volts

Amps (AC 1Φ, PF 1.0)

Assumes an AC single-phase resistive load at PF 1.0. Typing a commercial L-L voltage (208/400/480V) re-routes the result to three-phase; 277V stays on single-phase because it's the L-N lighting leg of a 480Y/277V wye; 12/24V re-routes to DC.

Formulas

DC: Watts to Amps

I_(A) = P_(W) ÷ V_(V)

2,160 ÷ 120 = 18 A

AC Single Phase (PF = 0.85)

I_(A) = P_(W) ÷ (PF × V_(V))

2,160 ÷ (0.85 × 120) = 2,160 ÷ 102 = 21.18 A

Circuit Sizing

Breaker Sizing

NEC 240.6(A) standard ampere ratings for branch-circuit and feeder breakers start at 15, 20, 25, 30, 35, 40, 45, and 50A and continue at 60A and above for feeder and large-appliance circuits. At 18A, the smallest standard breaker the raw current fits under is 20A, but that breaker only covers 20A non-continuously; NEC 210.19(A) requires conductor and OCP sized at 125% of any continuous load (equivalently 80% of breaker rating), so for a continuous load the smallest compliant breaker is 25A. Final selection still depends on the equipment nameplate, whether the load is continuous, conductor ampacity, and local code.

Breaker Size	Max Continuous Load (80%)	Status for 18A
15A	12A	Too small
20A	16A	Non-continuous only
25A	20A	OK for continuous
30A	24A	OK for continuous
35A	28A	OK for continuous
40A	32A	OK for continuous
45A	36A	OK for continuous
50A	40A	OK for continuous

Energy Cost

Running 2,160W costs approximately $0.37 per hour at the US average rate of $0.17/kWh (rates last reviewed April 2026). That is $2.94 for 8 hours or about $88.13 per month. See detailed cost breakdown.

AC Conversion Detail

The DC baseline for 2,160W at 120V is 18A. On an AC circuit with a power factor of 0.85, the current rises to 21.18A because reactive current flows alongside the real-power current.

Circuit Type	Formula	Result
DC	2,160 ÷ 120	18 A
AC Single Phase (PF 0.85)	2,160 ÷ (120 × 0.85)	21.18 A

Power Factor Reference

Power factor is the main reason 2,160W draws more current on AC than DC. At PF 1.0 (pure resistive, like a heater), the load pulls 18A at 120V on the single-phase basis the rest of the page uses. At PF 0.80 (typical induction motor), the same 2,160W pulls 22.5A. That is an extra 4.5A just to overcome the reactive component. Use the typical values below as a starting point, not for precise engineering calculations.

Load Type	Typical PF	2,160W at 120V (single-phase)
Resistive (heaters, incandescent)	1	18 A
Fluorescent lamps	0.95	18.95 A
LED lighting	0.9	20 A
Synchronous motors	0.9	20 A
Typical mixed loads	0.85	21.18 A
Induction motors (full load)	0.8	22.5 A
Computers (without PFC)	0.65	27.69 A
Induction motors (no load)	0.35	51.43 A

Same Wattage, Other Voltages

bolt2,160W at 12V = 180ADC bolt2,160W at 24V = 90ADC bolt2,160W at 100V = 21.6A1Φ, PF 1.0 bolt2,160W at 208V = 7.05A3Φ per line, PF 0.85 bolt2,160W at 220V = 9.82A1Φ, PF 1.0 bolt2,160W at 230V = 9.39A1Φ, PF 1.0 bolt2,160W at 240V = 9A1Φ, PF 1.0 bolt2,160W at 277V = 7.8A1Φ, PF 1.0 bolt2,160W at 400V = 3.67A3Φ per line, PF 0.85 bolt2,160W at 460V = 3.19A3Φ per line, PF 0.85 bolt2,160W at 480V = 3.06A3Φ per line, PF 0.85 bolt2,160W at 575V = 2.55A3Φ per line, PF 0.85

swap_horiz 18A to watts at 120V payments 2,160W running cost cable Wire size for 18A at 120V electrical_services 2.16 kW to amps science Ohm's law: 120V & 18A functions Watts to amps formula

Other Wattages at 120V

Watts	AC 1Φ Amps PF 1.0 resistive	AC 1Φ Amps PF 0.85 motor
750W	6.25A	7.35A
800W	6.67A	7.84A
900W	7.5A	8.82A
1,000W	8.33A	9.8A
1,100W	9.17A	10.78A
1,200W	10A	11.76A
1,300W	10.83A	12.75A
1,400W	11.67A	13.73A
1,500W	12.5A	14.71A
1,600W	13.33A	15.69A
1,700W	14.17A	16.67A
1,800W	15A	17.65A
1,900W	15.83A	18.63A
2,000W	16.67A	19.61A
2,200W	18.33A	21.57A
2,400W	20A	23.53A
2,500W	20.83A	24.51A
2,700W	22.5A	26.47A
3,000W	25A	29.41A
3,500W	29.17A	34.31A

Frequently Asked Questions

How many amps is 2,160W at 120V? expand_more

2,160W at 120V draws 18 amps on AC single-phase at PF 1.0 (resistive). For comparison at the same voltage: 18A on DC, 21.18A on AC single-phase at PF 0.85. Actual current depends on the load's power factor.

What power factor should I use for 2,160W calculations? expand_more

For resistive loads (heaters, incandescent bulbs, electric kettles) use PF 1.0. For motors, use 0.80. For mixed office/residential use 0.85. For computers and LED arrays the effective PF can be 0.65 or lower. Power factor only applies to AC.

Why does AC draw more amps than DC for 2,160W? expand_more

AC circuits with reactive loads have a power factor below 1.0, so they draw extra current. At PF 0.85, 2,160W at 120V draws 21.18A instead of 18A (DC). That is about 18% more current for the same real power.

Why does a 2,160W resistive heater draw fewer amps than a 2,160W motor at 120V? expand_more

Resistive loads like space heaters and toasters have a power factor of 1.0, so 2,160W at 120V on a single-phase AC basis draws 18A. An induction motor at the same wattage has a PF around 0.80, drawing 22.5A on the same basis. The extra current is reactive, it does no real work but still has to flow through the conductors and breaker.

What is the 80% continuous load rule for 2,160W? expand_more

NEC 210.19(A) sizes the conductor and overcurrent device at not less than 125% of any continuous load (a load that runs three hours or more), equivalently 80% of the breaker rating. At 18A (the current the branch conductors actually carry on AC single-phase at PF 1.0 (resistive)), the minimum breaker that satisfies this is 25A under typical assumptions. Brief non-continuous use can run closer to the full breaker rating, but space heaters, EV chargers, and long-running appliances should be sized for the continuous case.

This calculator provides estimates for reference purposes only. Always consult a licensed electrician and verify compliance with the National Electrical Code (NEC) and local electrical codes before performing any electrical work.