In theory, a GPON network can achieve a maximum split ratio of 1:128. This document uses the following key GPON terms:Fiber optic splitter is a device that splits fiber optic light into many portions according to a specified ratio. However, higher splits reduce the power margin and limit reach, so engineers must carefully calculate the optical budget. GPON supports higher data transmission rates, with a theoretical maximum of 10 Gbps for both upstream and downstream rates. A split ratio determines how many customers share one PON port, but it also controls optical loss, cabinet density, and how forgiving the network will be after years of repairs. This calculator helps you.