Tool
Fibre loss budget calculator
A fibre loss budget is the total optical loss a link can tolerate between the transmitter and receiver. It is calculated by adding the fibre attenuation over the link length, the loss of each mated connector pair, each splice, and any other components such as splitters or muxes, then adding a safety margin for ageing and future repairs.
Enter your own figures below. Everything is calculated in your browser from what you type.
Your link
Link
Components
Power budget (optional)
Total link loss
8.60 dB dB
11.60 dB dB including 3.00 dB dB margin
- Fibre loss
- 5.00 dB
- Connector loss
- 3.00 dB
- Splice loss
- 0.60 dB
- Other loss
- 0.00 dB
How this is worked out
Every assumption is on this page and every input is yours to change. A calculator with a hidden coefficient is a persuasion device rather than a tool.
The estimator uses TIA-568 maximum allowable attenuation values for each fibre type and wavelength. Your components may perform better than these maximums, so the result is a conservative worst case. The safety margin defaults to 3 dB to account for fibre ageing, temperature variation and future repairs.
If you enter a transmitter power and receiver sensitivity, the calculator compares the total loss against the power budget and shows a PASS or FAIL result with the remaining headroom.
Questions about fibre loss
What is a fibre loss budget?
A fibre loss budget is the total optical loss a link can tolerate between the transmitter and receiver. It is calculated by adding fibre attenuation, connector loss, splice loss and any other components, then adding a safety margin.
What are typical vs maximum values?
The calculator uses TIA-568 maximum allowable attenuation values. Your components may perform better than these maximums, so the result is a conservative worst case. Always check manufacturer datasheets for actual specifications.
Why include a safety margin?
A safety margin accounts for fibre ageing, temperature variation, connector wear and future repairs. Without it, a link that works today may fail in a few years. The default is 3 dB.
How do I measure actual loss?
Use an optical light source and power meter (OLTS) for end-to-end loss measurement, or an OTDR for fault location and individual event loss. Always test bidirectionally and average the results.
Related tools and services
Do this kind of work? Join the DataOptix engineer network.
Vetted independent engineers. Scoped jobs, no bidding.
Planning a fibre build?
Tell us the site, the task and the urgency. A coordinator replies within 2 business hours.