Professional Fiber Optic Link Budget Tool to calculate total optical link performance, power budgets, and system margins for fiber optic communication systems. The power budget refers to the amount of fiber optic cable plant loss that a datalink (transmitter to receiver) can tolerate in order to operate properly. After entering your values, please ensure you click the 'Calculate Link Loss' button at the bottom of the page to generate your total link loss. This paper will explain how to determine fiber link budget.