Watts to Amps Calculator: DC/AC Wattage to Amps Conversion

This Watts to Amps Calculator conversion tool converts electric power in watts (W) to electric current in amps (A). This calculator is useful for engineers, electricians, and individuals working with electrical systems.

Watts to Amps Calculator

Watts to Amps Calculator


This wattage calculator is provided for estimation purposes only and should not be considered professional advice. We are not liable for any inaccuracies or errors resulting from user input or application of the calculator's results. Users are responsible for verifying the output with a qualified professional and adhering to local codes and regulations.


  • Watts to Amps Conversion: Convert power in watts to current in amps.
  • Amps to Watts Conversion: A complementary tool for converting current back to power.
  • Support for Different Current Types: Calculate for Direct Current (DC), Alternating Current (AC) Single Phase, and AC Three Phase.
  • Scientific Notation: Input values in standard or scientific notation (e.g., 5e3 for 5000).

Usage Instructions

  1. Select Current Type: Choose from DC, AC Single Phase, or AC Three Phase.
  2. Enter Power: Input the power in watts. For kilowatts, convert to watts (1 kW = 1000 W).
  3. Enter Voltage: Input the voltage in volts. Millivolts can be converted to volts (1 mV = 0.001 V).
  4. Calculate: Press the calculate button to convert watts to amps.
  5. View Results: Current in amps and milliamps will be displayed.

Calculation Formulas

DC Watts to Amps: I(A) = P(W) / V(V)

  • Example: For 200 watts at 40 volts, I = 200W / 40V = 5A

AC Single Phase Watts to Amps: I(A) = P(W) / (PF × V(V))

  • Power factor (PF) typically equals 1 for resistive loads.
  • Example: For 2000 watts at 110 volts with a PF of 0.8, I = 2000W / (0.8 × 110V) = 22.72727A

AC Three Phase Watts to Amps:

  • Line to Line Voltage: I(A) = P(W) / (√3 × PF × VL-L(V))
  • Line to Neutral Voltage: I(A) = P(W) / (3 × PF × VL-N(V))
  • The power factor usually equals 1 for resistive loads.

Typical Power Factor Values

  • Resistive Load: 1
  • Fluorescent Lamp: 0.95
  • Incandescent Lamp: 1
  • Induction Motor (Full Load): 0.85
  • Induction Motor (No Load): 0.35
  • Resistive Oven: 1
  • Synchronous Motor: 0.9

Note: Specific power factor values should be used for accurate calculations rather than these typical values.

Watts to amps table (120V)

Power (W)Voltage (V)Current (A)
10 watts120 volts0.0833 amps
20 watts120 volts0.167 amps
30 watts120 volts0.250 amps
40 watts120 volts0.333 amps
50 watts120 volts0.417 amps
60 watts120 volts0.500 amps
70 watts120 volts0.583 amps
80 watts120 volts0.667 amps
90 watts120 volts0.750 amps
100 watts120 volts0.833 amps
200 watts120 volts1.667 amps
300 watts120 volts2.500 amps
400 watts120 volts3.333 amps
500 watts120 volts4.167 amps
600 watts120 volts5.000 amps
700 watts120 volts5.833 amps
800 watts120 volts6.666 amps
900 watts120 volts7.500 amps
1,000 watts120 volts8.333 amps
1,100 watts120 volts9.167 amps
1,200 watts120 volts10.000 amps
1,300 watts120 volts10.833 amps
1,400 watts120 volts11.667 amps
1,500 watts120 volts12.500 amps
1,600 watts120 volts13.333 amps
1,700 watts120 volts14.167 amps
1,800 watts120 volts15 amps
2,400 watts120 volts20 amps

Watts to amps table (240V)

Power (W)Voltage (V)Current (A)
3,600 watts240 volts15 amps
4,800 watts240 volts20 amps
7,200 watts240 volts30 amps
9,600 watts240 volts40 amps
12,000 watts240 volts50 amps
14,400 watts240 volts60 amps
16,800 watts240 volts70 amps
19,200 watts240 volts80 amps
21,600 watts240 volts90 amps
24,000 watts240 volts100 amps
30,000 watts240 volts125 amps
36,000 watts240 volts150 amps
48,000 watts240 volts200 amps

Hubert Miles | Licensed Home Inspector, CMI, CPI

Hubert Miles is a licensed home inspector (RBI# 2556) with more than two decades of experience in inspection and construction. Since 2008, he has been serving South Carolina through his company, Patriot Home Inspections LLC. As a Certified Master Inspector, Hubert is dedicated to providing his expertise in home inspections, repairs, maintenance, and DIY projects.