Common single‑mode attenuation is about 0. Calculating a loss budget for a cable plant involves estimating all the component losses - fiber, splices and connectors - and summing them up. Go here for more comprehensive discussion on how to calculate a loss budget. Connector Loss For each connector, we usually figure 0. 3 dB loss for most. This value should be determined by the system designer. ) (The maximum splice loss permitted for installation. Passive splitters introduce higher loss; for. Type of fiber – Most single mode fibers have a loss factor of between 0.