Fiber Optic Loss Budget

Total fiber link loss and the margin against the application's maximum channel loss.

Run the calculator

Example

You enter

Link length (m) 300
Attenuation (dB/km) 3
Connector pairs 2
Loss per connector (dB) 0.75
Max channel loss (dB) 2.6

You get

Total link loss (dB) 2.4
Margin db 0.2

Details, formula, and sources

Total link loss (fiber + connectors + splices) and the margin against an application's maximum channel loss (TIA-568 / TIA-526 / IEEE 802.3).

loss = attenuation(dB/km) * length_km + connectors * loss_per_connector + splices * loss_per_splice; margin = max_channel_loss - loss; pass when margin >= 0.

Optical link loss budget - fiber attenuation plus connector and splice losses against the application's maximum channel loss - per the TIA-568 / TIA-526 fiber-test methods and the IEEE 802.3 channel-loss limits, by name; first-principles.

First-principles dB accounting. Attenuation coefficients and component losses are component-specific and user-supplied; the OTDR/power-meter field test governs the certified link.

Estimate. AHJ and licensed electrician govern. Verify against the NEC edition adopted in your jurisdiction.

Field names used by the API: length_m, attenuation_db_km, connector_count, loss_per_connector_db, max_channel_loss_db, total_loss_db, margin_db

Component losses per-connector 0.75 dB and per-splice 0.3 dB defaults; user-suppliedTIA-568 component data