DC Voltage and Current

• 1). Key the DC voltage value into the calculator. For example, if the circuit voltage is 4 volts, key in "4."
  
  
• 2). Press the "Multiply" key. Enter the DC current into the calculator. For this example, your circuit has 2 amps of current, so enter "2."
  
  
• 3). Press the "Equals" key. The result is DC watts. In this example, 4 volts x 2 amps = 8 watts.
  
  

DC Current and Resistance

• 1). Enter the current measurement into the calculator. Multiply the number by itself to square it. For example, if your circuit has 2 amps of current, multiply 2 times 2 to get 4.
  
  
• 2). Press the "Multiply" key. Enter the DC resistance in ohms. In this example, your circuit has a resistance of 2 ohms. Enter "2" into the calculator.
  
  
• 3). Press the "Equals" key. The result is DC power in watts. For this example, 4 x 2 = 8 W.
  
  

DC Volts and Resistance

• 1). Enter the DC voltage into the calculator. Multiply the number by itself to square it. For example, if your circuit has 4 volts, multiply 4 times 4 to get 16.
  
  
• 2). Press the "Divide" key. Enter the resistance of the circuit in ohms. In this example, your circuit has a resistance of 2 ohms. Enter "2" into the calculator.
  
  
• 3). Press the "Equals" key. The result is DC watts. For the example, 16 / 2 = 8 W.
  
  

AC Volts and Amps

• 1). Key in the AC voltage value into the calculator. For this example, the voltage is 110 volts RMS, so enter "110."
  
  
• 2). Press the "Multiply" key. Enter the AC current. For this example, your AC current is 2 amps. Enter "2." If the voltage is an RMS value, as in this example, skip Step 3 and proceed to Step 4.
  
  
• 3). Press the "Multiply" key. Enter the value ".707." Remember to do this only if the voltage value is peak voltage. Otherwise, skip this step.
  
  
• 4). Press the "Equals" key. The result is AC watts. In our example, using an RMS voltage value of 2 volts, 110 x 2 = 220 W.