Fiber Optic Loss Budget
Total fiber link loss and the margin against the application's maximum channel loss.
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
Checked against published worked examples from: TIA-568 / TIA-526 / IEEE 802.3 (by name).
Details, formula, and sources
ScopeTotal link loss (fiber + connectors + splices) and the margin against an application's maximum channel loss (TIA-568 / TIA-526 / IEEE 802.3).
Formula or tableloss = attenuation(dB/km) * length_km + connectors * loss_per_connector + splices * loss_per_splice; margin = max_channel_loss - loss; pass when margin >= 0.
Source and editionOptical 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.
Free accessFirst-principles dB accounting. Attenuation coefficients and component losses are component-specific and user-supplied; the OTDR/power-meter field test governs the certified link.
What governsEstimate. AHJ and licensed electrician govern. Verify against the NEC edition adopted in your jurisdiction.
API field nameslength_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