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Fiber Optic Loss Budget Calculator

Total optical link loss from fiber attenuation, connectors, and splices. Compared against a user-supplied link budget (Tx power − Rx sensitivity from the transceiver spec) to tell you whether the link is feasible.

Fiber length (km)

Attenuation (dB/km — from cable spec)

Connector pairs (count)

Loss per connector (dB, default 0.5)

Fusion splices (count)

Loss per splice (dB, default 0.1)

Link budget (dB, optional — Tx − Rx)

Limitations: Additive worst-case model. Does NOT model chromatic or polarization-mode dispersion, which dominate at high bitrates on long single-mode links. Typical figures are defaults only — always use the real cable and hardware specs.

What to do next: Typical TIA-568 attenuation: SM 1310 nm 0.35 dB/km, SM 1550 nm 0.22 dB/km, MM 850 nm 3.0 dB/km. Keep ≥ 3 dB margin vs. link budget for aging, bends, and future repairs.