40 Watts to Amps

40 watts is 0.3333 amps at 120V (DC). The exact amperage depends on your voltage and whether the circuit is DC or AC.

40 Watts to Amps at Every Voltage

VoltageDCAC (PF 0.85)AC 3-Phase (PF 0.85)
12V
DC, automotive, solar
3.33A 3.92A 2.26A
24V
DC, industrial control
1.67A 1.96A 1.13A
100V
Japan residential
0.4A 0.4706A 0.2717A
120V
US residential
0.3333A 0.3922A 0.2264A
208V
US commercial three-phase
0.1923A 0.2262A 0.1306A
220V
Legacy international / parts of Asia
0.1818A 0.2139A 0.1235A
230V
UK / EU residential
0.1739A 0.2046A 0.1181A
240V
US residential (dryer, range, HVAC)
0.1667A 0.1961A 0.1132A
277V
US commercial lighting
0.1444A 0.1699A 0.0981A
400V
UK / EU commercial three-phase
0.1A 0.1176A 0.0679A
460V
US industrial motor (NEC 430.250 column)
0.087A 0.1023A 0.0591A
480V
US industrial three-phase
0.0833A 0.098A 0.0566A
575V
Canadian industrial three-phase
0.0696A 0.0818A 0.0473A

Other Wattages

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.