Up next in Intermediate Math Skills (21 videos)
Brush up on your math with these tutorials.
You Will Need
- Mathematical formulas
Understand the definition
Know that 1 watt is the amount of power produced by a current of 1 ampere across a potential difference of 1 volt.
Understand that the wattage listed on an appliance is the maximum power it draws. Because many appliances have a range of settings, the actual amount of power consumed at any given time depends on the setting used.
Use a formula
Consider using a formula to estimate wattage. To do this you will need to know the current draw, the voltage used by the appliance, and/or the resistance of the appliance.
Use voltage and current
Calculate the wattage from the product of voltage and the current for the appliance. Voltage is measured in volts and current in amperes (or amps).
Use current and resistance
Obtain the wattage as the product of the square of current times the resistance. Resistance is measured in ohms.
Use voltage and resistance
Calculate the wattage from the quotient of the square of voltage divided by resistance.