Link details
Loss breakdown
Total link loss—
Fiber attenuation—
Connector loss—
Splice loss—
Safety margin—
Available budget (Tx − Rx)—
Remaining margin—
Enter Tx and Rx for a pass/fail result
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Frequently Asked Questions
What is a fiber loss budget?
A loss budget is the total optical loss a link is allowed before the receiver can no longer read the signal. It sums fiber attenuation, connector and splice losses, plus a safety margin.
Typical connector / splice loss?
A typical mated connector loses about 0.5 dB and a fusion splice about 0.1 dB. Use manufacturer or field-tested values where available.
Single-mode vs multimode attenuation?
Typical attenuation is about 0.35 dB/km single-mode at 1310 nm, 0.22 dB/km at 1550 nm, 3.0 dB/km multimode at 850 nm and 1.0 dB/km at 1300 nm.
What margin should I use?
A 3 dB margin is common to allow for ageing, repairs and measurement uncertainty. Increase it for long, critical or hard-to-access links.
Attenuation and component values are typical figures. Always confirm the as-built link with field testing (OTDR / OLTS) before commissioning.