OPTICAL ENGINEERING TOOL

Fiber Loss Calculator

Calculate total optical loss from fiber, splices, connectors, splitters and passive components, then evaluate engineering margin, receive power and link health.

Fiber attenuationConnector & splice lossEngineering marginPass / fail check

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Link parameters

Enter real engineering parameters to calculate the link loss.

Scenario preset

Project name

Transmission distance

Wavelength

Fiber attenuation

dB/km

Number of splices

pcs

Loss per splice

Number of connectors

pcs

Loss per connector

Primary splitter

Secondary splitter

Other passive loss

Engineering margin

Available optical budget

Transmit power

dBm

Receiver sensitivity

dBm

▥

Calculation result

Design loss includes engineering margin; physical loss excludes it.

Total design loss

0.00dB

✓ Healthy

⌁

Fiber loss 0.00 dB

⋈

Splice loss 0.00 dB

↝

Connector loss 0.00 dB

Splitter & other loss 0.00 dB

✦Transmitter

⌁0.00 dB

⋈0.00 dB

↝0.00 dB

➤Receiver

Physical link loss 0.00 dB

Budget remaining 0.00 dB

Estimated receive power 0.00 dBm

Receiver margin 0.00 dB

Engineering conclusion

—

PROJECT RECORDS

Recent calculations

METHODOLOGY

Methodology and engineering notes

Physical link loss

Fiber length × attenuation + splice loss + connector loss + splitter loss + other passive loss.

Total design loss

Physical link loss + engineering margin.

Receive power

Transmit power − physical link loss.

Health rules

Remaining ≥ 3 dB: healthy; 0–3 dB: caution; below 0 dB: failed.

Important note

Default attenuation and splitter values are common engineering references. Final designs should follow device specifications, enterprise standards and field measurements.

ENGINEERING REFERENCES

Fiber loss standards and measurement references

The 3 dB health threshold is a configurable planning rule used by this calculator, not a universal requirement from these standards. Confirm wavelength-specific fibre, connector, splice and splitter values from the deployed components, then use calibrated field measurements for acceptance. Last reviewed: 2026-08-31.

FAQ

Frequently asked questions

What is the difference between physical loss and design loss?

Physical loss includes actual fiber and component losses. Design loss also includes engineering margin for ageing, temperature, maintenance connections and measurement variation.

How should I choose 1310, 1490 or 1550 nm?

Select the actual service wavelength and direction. Common PON upstream uses 1310 nm, while downstream may use 1490 or 1550 nm. Follow the system specification.

Why can splitter loss be adjusted?

The page uses typical nominal values. Actual loss varies by vendor, packaging and wavelength, so final designs should use specification or measured values.

How much remaining budget is considered safe?

A minimum 3 dB engineering margin is commonly recommended. Smaller margins are more sensitive to contamination, bending, ageing and temperature changes.

Why can receive power pass while the budget shows caution?

Receive threshold and design budget are separate checks. High transmit power may keep receive power acceptable while long-term design margin remains limited.

Can this result be used for final acceptance?

This calculator supports planning, review and troubleshooting. Final acceptance should combine power meter and OTDR measurements, equipment specifications and enterprise standards.

ENGINEERING WORKFLOW

Continue the engineering workflow

Current workflowOptical Link Design Workflow

Build an optical link from physical loss assumptions through split planning, power budget and maximum reach verification.

Step 1 of 4

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