A 1:32 splitter divides input power by ~32 (adding ~15dB of insertion loss), so the remaining power supports signals up to 20km. This calculator helps construction and commissioning teams document expected attenuation before pulling, terminating, and testing fiber. Let's say you have a laser output at 0 dBm (which is 1 milliwatt of optical power). If you use a 1×8 splitter with ~10. 2dB/km for single-mode fiber at 1550nm (the primary PON wavelength). Connector loss is always measured as a mated pair. Splitter loss values are "Typical" and include a connector in and out. in Watts – W), the loss value in dB is calculated by the formula: Loss (dB) = 10 lg ( mW1 / mW2 ) When both gains are equal, the loss is 0 dB, so there is no loss (doesn't happen obviously).