OS2 attenuation
Default
0.35 dB/km @ 1310 nm, 0.25 dB/km @ 1490 nm, 0.22 dB/km @ 1550 nm, 0.23 dB/km @ 1577 nm
Note
Use datasheet values for final project design.
Fiber Link Budget Calculator
Fiber Optic Link Loss Budget Calculator
Estimate optical link loss and required budget. Check remaining margin and loss-limited reach. Supports single mode, multimode, MPO/MTP and PLC splitter planning.
Use this tool for general optical link planning. Screens margin from available budget. Adds estimated link loss and engineering reserve. No OLT/ONU received-power check.
Calculator Input
Link Budget Inputs
Scenario only applies practical starting values; all fields remain editable.
Wavelength options are adjusted by fiber type.
Unit: dB/km.
Use km for route links and m for rack, patching or equipment-room links.
If edited manually, preset switches to Custom Budget.
Example: one LC/SC adapter connection = 1 mated pair.
For full PON power-window calculation, use the dedicated PON calculator.
Advanced engineering parameters
Unit: dB per splice.
Use this when MPO / MTP trunks or cassettes are part of the passive link.
Use Cases
When to Use This Tool
Point-to-point fiber links
Use it to estimate passive optical loss for a route with fiber attenuation, mated connector pairs and fusion splices.
MPO / data center links
Use it for insertion-loss screening. Actual multimode reach must still follow transceiver speed and standard reach.
FTTH passive loss checks
Use it only for passive loss screening. For OLT/ONU received power, use the dedicated PON splitter calculator.
Calculation Rules
Calculation Assumptions
OM3 / OM4 / OM5 attenuation
Default
3.0 dB/km @ 850 nm, 1.0 dB/km @ 1300 nm
Note
Multimode reach is often limited by bandwidth and transceiver standard reach.
Connector pair
Default
0.20 / 0.35 / 0.50 dB per mated pair
Note
Use the appropriate loss grade for the connector and polish type.
MPO / MTP connection
Default
0.25 / 0.35 / 0.75 dB per mated MPO connection
Note
Confirm MPO gender, polarity, fiber count and loss grade.
PLC splitter
Default
1:2 = 3.8 dB, 1:4 = 7.4 dB, 1:8 = 10.7 dB, 1:16 = 13.9 dB, 1:32 = 17.2 dB, 1:64 = 20.8 dB
Note
For detailed PON ODN power budget, use the dedicated PON calculator.
Result Guide
How to Read the Result
Pass
Margin
Remaining margin ≥ engineering reserve
Meaning
The link budget assumptions look reasonable for early screening.
Action
Confirm connector loss grade, route length and passive component count.
Warning
Margin
Margin is positive but below reserve, or topology is unusual.
Meaning
The link may work, but field variation can create risk.
Action
Reduce connectors, use low-loss components, or increase available optical budget.
Fail
Margin
Estimated loss exceeds available budget.
Meaning
The link budget assumptions should be revised before deployment planning.
Action
Review route length, split ratio, transceiver budget and passive component count.
