The Power Factor Calculator determines how effectively electrical power is being converted into useful work output. It calculates the ratio between real power (P) and apparent power (S) using the formula PF = P / S. The result indicates how efficiently energy is used — with a value closer to 1.0 representing better efficiency. The calculator also shows the phase angle (θ) between voltage and current to indicate the amount of reactive power. This tool is helpful in understanding and improving power efficiency in electrical systems.