Infrastructure & Communications Lab

Optical network design · Offline tool

Fiber optic loss & SFP budget

Estimate cable, connection and splice losses, reserve headroom and optionally compare a manufacturer's optical power budget. This is not an OTDR result or proof of compatibility.

Planning assumptions, not measured values. Wavelength profiles are Fiber Optic Association typical attenuation values and the connector/splice defaults are TIA-568 maximum allowances quoted by FOA: design estimates, not certified test results. Check cable type, optics, connector count, launch conditions and manufacturer limits. Optional overload screening uses a separate, conservative minimum-loss assumption. Reference: FOA design guide.
Link assumptions
Choose a starting wavelength, then adjust each component to your project.

Changing preset updates attenuation only; other inputs remain intact. FOA typical 0.4 dB/km; TIA-568 maximum 0.5 OSP / 1.0 premises dB/km.

End-to-end physical cable distance

Count both ends and intermediate patch connections

Count fusion or mechanical splices

Use cable manufacturer specifications where available

Default 0.75 dB = TIA-568 maximum per mated pair (FOA); a design estimate, not a test result

Default 0.3 dB = TIA-568 maximum per splice (FOA); a design estimate

Splitter/coupler or other specified losses; never omit known losses

Extra allowance for aging, restoration and uncertainty

Use verified optic minimum, not typical or maximum

Enter the verified receiving sensitivity for required link performance

From the transmitting optic datasheet, not typical output; used for high-power overload screening

Manufacturer maximum operating input / overload threshold, NOT the damage threshold

Use a justified minimum attenuation, NOT the typical design loss above. If unknown, use conservative 0 dB and inspect the risk.

Budget assessment
All losses shown in dB; transmitter and receiver specifications are in dBm.
Awaiting manufacturer optic values
Cable attenuation
0.8 dB
Connection loss
1.5 dB
Splice loss
0.6 dB
Passive total
2.9 dB
Required incl. reserve
5.9 dB

Receiver overload screening

Not assessed — optional values missing

Optional: enter manufacturer maximum TX power, receiver maximum operating input and a justified minimum path loss. Use 0 dB if no minimum can be established.

Source: FOA receiver overload and attenuators. This is an offline estimate, not an optical power measurement.

To compare hardware, enter BOTH manufacturer minimum TX power and RX sensitivity. Optical link compatibility cannot be inferred without them.