INFRASTRUCTURE

Fiber Optic Link Budget Calculator

Estimate passive optical loss, expected receiver power, and remaining design margin for a planned fiber link.

Use the actual minimum TX power, RX sensitivity, and RX overload values from both transceiver data sheets. This is a planning estimate, not an optical measurement.

Link Properties

SFP Transceiver Specs

Passive Path Loss 5.70 dB
Estimated RX Power -10.70 dBm
Available Power Budget 9.00 dB
Required Loss + Margin 8.70 dB
Remaining Design Margin 0.30 dB
PLANNING RESULT: LIMITED MARGIN
The entered link meets sensitivity with 0.30 dB beyond the requested design margin. Verify the real link and transceiver specifications.
Model boundary: passive path loss = fiber + mated connector pairs + splices. Estimated RX power uses passive loss only, so changing the required design margin never changes RX power. Remaining design margin compares the available transceiver budget with passive loss plus your requested margin. Dirty connectors, bends, splitters, patch-panel variation, Tx tolerance, wavelength compatibility, and measured optical power are outside this model.

When to Use This Tool

Remote Sports Broadcasting

Calculating the optical loss across 15+ kilometers of dark fiber leased from a telco provider to ensure your ST 2110 IP video trunks reach the remote production gallery.

Stadium / Campus Tielines

Designing the fiber infrastructure between a remote broadcast compound and the stadium patch room, accounting for multiple LC connector mating pairs in wall boxes.

SFP Specification / Purchasing

Determining whether a standard 10km "LR" (Long Reach) SFP transceiver is sufficient for a specific cable run, or if an expensive 40km "ER" (Extended Reach) module must be purchased.

Checking Short-Link Overload

Comparing the estimated receiver power with the overload limit published for the exact receiving module. Verify any short-link attenuation requirement with the manufacturer.

Bookmark this tool

Save this for your next project or share with your engineering team.

What is the Fiber Optic Link Budget?

Calculates total optical loss (dB) for SFP and QSFP link designs, considering cable distance, connector counts, and fusion splices compared to the SFP's maximum power budget.

The result is a planning estimate. Confirm wavelength, fiber type, Tx range, receiver limits, and any required attenuator against the exact module data sheets, then measure commissioned links with appropriate optical test equipment.

Real-World Use Cases

Used by site-wiring engineers when planning long fiber runs between OB vans and MCR or between buildings on a campus to ensure the signal stays within safe RX power levels.

Use the worksheet to find links that need a different transceiver, fewer loss points, or more design margin before installation.

Technical Methodology

The selectable defaults use 0.35 dB/km for OS2 at 1310 nm, 0.25 dB/km at 1550 nm, 3.0 dB/km for multimode at 850 nm, 0.5 dB per mated connector pair, and 0.1 dB per fusion splice. Replace these planning values when project or manufacturer data specifies otherwise.

Available power budget is TX design power minus RX sensitivity. Physical estimated RX power is TX design power minus passive path loss. The requested design margin is applied only to the budget decision.

Related Engineering Tools

ST 2110 Video Capacity Worksheet NDI Network Planner Dante & AES67 Switch Configurator All Broadcast Tools