21 Watts to Amps

21 watts is 0.175 amps at 120V (DC). The exact amperage depends on your voltage and whether the circuit is DC or AC.

21 Watts to Amps at Every Voltage

VoltageDCAC (PF 0.85)AC 3-Phase (PF 0.85)
12V
DC, automotive, solar
1.75A 2.06A 1.19A
24V
DC, industrial control
0.875A 1.03A 0.5943A
100V
Japan residential
0.21A 0.2471A 0.1426A
120V
US residential
0.175A 0.2059A 0.1189A
208V
US commercial three-phase
0.101A 0.1188A 0.0686A
220V
Legacy international / parts of Asia
0.0955A 0.1123A 0.0648A
230V
UK / EU residential
0.0913A 0.1074A 0.062A
240V
US residential (dryer, range, HVAC)
0.0875A 0.1029A 0.0594A
277V
US commercial lighting
0.0758A 0.0892A 0.0515A
400V
UK / EU commercial three-phase
0.0525A 0.0618A 0.0357A
460V
US industrial motor (NEC 430.250 column)
0.0457A 0.0537A 0.031A
480V
US industrial three-phase
0.0438A 0.0515A 0.0297A
575V
Canadian industrial three-phase
0.0365A 0.043A 0.0248A

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.