⚠ Important — Please Read Before Using This Tool

LinkZoneTools LLC · Link Budget & Performance Calculator · Terms of Use & Disclaimer

📋 Reference & Educational Use Only

This tool is provided for reference, planning, and educational purposes only. It is not professional RF engineering advice and is not a guarantee of link performance. Results are estimates from theoretical models and published data.

⚠ Radio Specifications

The radio database is compiled from manufacturer published material. A source status records what was checked at the date shown; it is not a guarantee that every operating condition or firmware revision is covered. Manufacturers revise specifications without notice. Always verify against the current datasheet before procurement or final design, and use the manufacturer’s planning software as the equipment design authority.

📈 Model Limitations

The clear-air budget uses free-space loss (ITU-R P.525) plus the entered gas, radio-planning and fixed-loss allowances. Rain screening uses ITU-R P.838-3 and P.530-19. It does not model terrain diffraction, foliage, obstructions, interference, alignment, equipment, power or network outages. Current location-specific P.837-8 rainfall data is preferred over legacy rain-zone letters.

⚖ Limitation of Liability — No Warranty

LINKZONETOOLS LLC PROVIDES THIS TOOL "AS IS" WITHOUT WARRANTY OF ANY KIND. LINKZONETOOLS LLC SHALL NOT BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, CONSEQUENTIAL OR EXEMPLARY DAMAGES ARISING FROM USE OF OR RELIANCE ON THIS TOOL, INCLUDING FAILED DEPLOYMENTS, EQUIPMENT LOSSES, LOST REVENUE OR BUSINESS INTERRUPTION. THE USER ASSUMES ALL RESPONSIBILITY FOR DESIGN DECISIONS AND OUTCOMES.

© LinkZoneTools LLC · Reference tool only · Not a substitute for professional RF engineering or manufacturer link planning software.

Link Budget & Performance Calculator

This tool answers: given a viable path, will the radio link close — and how well? It accounts for every gain and loss between transmitter and receiver, then predicts how much of the year the link stays up.

1
Choose a radio
Pick from the database to pre-fill planning inputs, or switch to Manual. Treat the source badge as provenance, then confirm the current datasheet and manufacturer planner.
2
Pick the modulation honestly
Select the mode you actually intend to run, not merely the fastest one. Receiver thresholds and radio planning allowances vary by mode.
3
Enter antennas and losses
Enter gain at each end and every applicable cable, connector, gas, implementation and fixed-loss allowance.
4
Set distance and frequency
Use the actual transmit frequency for the direction being evaluated. On FDD E-band links, evaluate both directions and design to the worse result.
5
Read the waterfall
Every budget term is shown explicitly. The running total is the planned clear-air received level.
6
Check the fade margin
Fade margin is not a universal pass/fail grade. It is the attenuation available to the selected MCS and must be evaluated with the applicable propagation model and service objective.
7
Review availability
The prediction is propagation-only. For paths at or below 5 km, P.530-19 permits multipath to be set to zero; longer paths need additional profile and ITU map inputs before a combined result can be stated.

The budget is a linear sum in the log domain. Every term below is additive in dB, which is the entire reason RF work is done in decibels rather than watts.

The full expression

RSL = Ptx + Gtx − Ltx − FSPL − Latm + Grx − Lrx

with free-space loss per ITU-R P.525:

FSPL(dB) = 20·log₁₀(dkm) + 20·log₁₀(fGHz) + 92.45

Fade margin is simply RSL − Pth, where Pth is the threshold for the selected modulation at the target BER (10⁻⁶ is the usual licensed-microwave reference).

Threshold and modulation

Receiver threshold is not a single number — it is a function of the modulation and coding scheme:

Pth = kTB + NF + SNRmin

where kTB = −173.98 dBm/Hz + 10·log₁₀(BHz) at 290 K. Moving from the lowest to the highest modulation on a licensed radio typically costs 25–35 dB of threshold. Selecting the top mode because it is available is the fastest way to produce a budget that will not survive contact with weather.

Availability model

Predicted outage is split into two independent mechanisms and summed:

  • Multipath — ITU-R P.530 flat-fade distribution, driven by path length, frequency, terrain roughness and the geoclimatic factor. Dominant below roughly 10 GHz and on long, flat, over-water paths.
  • Rain — γ = k·Rα (ITU-R P.838-3) applied over an effective path length that shortens as rain cells are statistically non-uniform. Dominant above roughly 10 GHz.

The tool reports both. Whichever term is larger is the one to engineer against — adding fade margin helps multipath far more efficiently than it helps rain, because rain attenuation scales with path length rather than fading statistically.

Radio data provenance

Entries carry a source-status badge. VERIFIED means the stated planning inputs were checked against the cited source and conditions. PARTIAL means one or more inputs came from a planner, secondary source, conflicting document, or incomplete table. Neither status replaces final confirmation for the exact SKU, firmware and channel.

Before procurement: re-check thresholds against the datasheet revision for the exact SKU and firmware you intend to deploy. Vendors revise sensitivity figures between firmware releases, and regional SKUs differ in permitted power.

Where budgets go wrong

  • Datasheet antenna gain assumed without accounting for radome loss or mispointing
  • Cable loss taken at the wrong frequency — attenuation scales roughly as √f
  • Connector and arrestor losses omitted (0.1–0.2 dB each, and they accumulate)
  • EIRP exceeding the regulatory limit for the band once high-gain antennas are fitted
  • Availability quoted for one direction only on an asymmetric link
References: ITU-R P.525 (free-space) · ITU-R P.530 (availability, multipath) · ITU-R P.838-3 (rain coefficients) · ITU-R P.837 (rain rate)
Every field has a ? tooltip for quick guidance and a 📚 Learn button for the concept behind it.
⚠ Reference tool only. Radio specifications compiled from manufacturer datasheets — verify against current datasheets before procurement.
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Link Budget & Performance Calculator

Received signal level, fade margin, system gain, availability and throughput for point-to-point and point-to-multipoint links.

Radio database · source-tracked entries · verify current revisions

Project ?

Unsaved
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Radio ?

Why isn’t my radio listed?

Every entry in this database is built from published manufacturer figures. Where a manufacturer does not publish receiver sensitivity, the radio is left out rather than filled in with estimates — a guessed sensitivity would silently corrupt every link budget built on it.

Tarana G1 / G2 — not modelled Tarana publishes throughput, range and spectral efficiency, but no transmit power or receiver sensitivity figures. Their ngFWA platform also uses scheduled multipoint with active interference cancellation and adaptive coding, so a conventional point-to-point link budget would misrepresent how the radio actually performs. Use Tarana’s own planning tools.
MikroTik Wireless Wire — not modelled No per-modulation receiver sensitivity published.
Ubiquiti airFiber AF-5X, AF-11FX, AF-24 — awaiting verification Datasheets for these exist and include sensitivity tables; they simply have not been verified into this database yet. The airFiber 5XHD is fully verified and available now.
Mimosa — partial data Mimosa publishes receiver sensitivity for MCS0 only, per channel width. Those MCS0 figures are included as genuine datasheet values, but no MCS1–MCS9 ladder is published, so enter sensitivity manually for higher modulations.
Wi-Fi access points — out of scope Products such as the UniFi U7 series are Wi-Fi access points, not point-to-point backhaul radios. They do not publish receiver sensitivity because it is not the governing spec for that product class, and a PtP link budget is the wrong model for them.

Have a datasheet with a sensitivity table we have missed? It can be added.

Transmitter — Site A

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EIRP ?
— dBm

Receiver — Site B

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Path ?

—
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dB/km, multiplied by path length
dB, manufacturer/model specific

Availability ?

mm/hr; direct value overrides the zone table
ℹRain uses ITU-R P.530-19 and P.838-3. For paths at or below 5 km, P.530-19 permits multipath fading to be set to zero. Longer paths require coordinates, terrain clearance, antenna elevations and ITU digital map inputs; this tool will not invent them.
📡
Enter link parameters
Select a radio or enter specs manually, then set distance and frequency. Results update as you type.