# Wattage formula calculator

Multiply these two numbers to get the watt-hour rating (Ah × V = Wh). Note: If the capacity of your battery is expressed in milliampere hours (mAh)—like in the image above— you will need to divide by 1,000 to calculate the ampere-hours (Ah) before multiplying. AC three phase amps to watts calculation Calculation with line to line voltage. The power P in watts (W) is equal to square root of 3 times the power factor PF times the phase current I in amps (A), times the line to line RMS voltage V L-L in volts (V): P (W) = √ 3 × PF × I (A) × V L-L(V) Calculation with line to neutral voltage To convert from VA to Watts you simply multiply the VA by the Load power factor , as shown by the formula of VA to Watts. Commonly the power factor can be obtained by performing a search on the Internet with the references of the equipment , however another way is to use a table with common power factors . Watts can be converted to volts using current and a Watt’s Law formula, which states that current is equal to power divided by voltage. We can change this formula around a bit using algebra to restate it as voltage is equal to power divided by current. This is the formula to convert wattage to voltage: Voltage (V) = Power (W) ÷ Current (A)