How the loss budget calculation works
The total attenuation of a fibre optic link consists of three parts:
Total loss = (link length × fibre attenuation) + (number of connectors × loss per connector) + (number of splices × loss per splice)
This total loss is compared against the available system budget (for example the ODN class in a GPON network). If enough margin remains, the link will operate reliably – the calculator signals this with a clear traffic-light verdict.
Which standard values are preset?
- Single-mode OS2 (ITU-T G.652.D): 1310 nm ≈ 0.35 dB/km, 1550 nm ≈ 0.22 dB/km, 1625 nm ≈ 0.24 dB/km
- Multimode OM3/OM4/OM5 (IEC 60793): 850 nm ≈ 3.0 dB/km, 1300 nm ≈ 1.0 dB/km
- Connectors: typically 0.30 dB, TIA-568 limit 0.75 dB, premium/E-2000 ≤ 0.10 dB
- Splices: fusion splice typically 0.10 dB, mechanical splice ≈ 0.30 dB
- GPON budget (ITU-T G.984): Class B+ 28 dB, Class C+ 32 dB
The datasheets of the components you actually deploy always take precedence – which is why every value in the calculator is editable.
Frequently asked questions
What is a loss budget?
The loss budget (link budget) is the maximum total attenuation a fibre optic link may exhibit while still operating reliably. It is derived from the transmitter output power minus the receiver sensitivity of the active equipment.
How much margin should I plan for?
A system margin of at least 3 dB is common practice – it covers fibre ageing, future repair splices and measurement tolerances. The calculator automatically flags tight links.
Does the calculator cover FTTH and data centres?
Yes. By selecting fibre type, wavelength and budget you can cover FTTH/GPON scenarios as well as multimode links inside the data centre.
Matching components from Fiber Products
Planning a real link? Our splice boxes, splice modules and patch cords are available in numerous configurations – including E-2000 technology in Swiss precision. Send us a non-binding enquiry.
Related product
E-2000 Connectivity
Connector face with protective shutter and push-pull latch, available in splice and front modules on the 7 TE grid and in splice boxes · APC and PC · production partner of DIAMOND SA
