40 Amps to Watts

40 amps is 4,800 watts at 120V (DC). The wattage depends on your circuit voltage.

40 Amps to Watts at Every Voltage

VoltageDCAC (PF 0.85)AC 3-Phase (PF 0.85)
12V
DC, automotive, solar
480W 408W 706.68W
24V
DC, industrial control
960W 816W 1,413.35W
100V
Japan residential
4,000W 3,400W 5,888.97W
120V
US residential
4,800W 4,080W 7,066.77W
208V
US commercial three-phase
8,320W 7,072W 12,249.06W
220V
Legacy international / parts of Asia
8,800W 7,480W 12,955.74W
230V
UK / EU residential
9,200W 7,820W 13,544.64W
240V
US residential (dryer, range, HVAC)
9,600W 8,160W 14,133.53W
277V
US commercial lighting
11,080W 9,418W 16,312.45W
400V
UK / EU commercial three-phase
16,000W 13,600W 23,555.89W
460V
US industrial motor (NEC 430.250 column)
18,400W 15,640W 27,089.27W
480V
US industrial three-phase
19,200W 16,320W 28,267.07W
575V
Canadian industrial three-phase
23,000W 19,550W 33,861.59W

Other Amperages

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.