Calculator Inputs
Use the form below to estimate theoretical range, radio horizon, Fresnel clearance, and a practical deployment distance.
Plotly Graph
The graph compares received power against distance and overlays the receiver sensitivity threshold.
Example Data Table
These examples illustrate typical outcomes for different wireless scenarios. Actual field performance depends on terrain, obstructions, alignment, and interference.
| Scenario | Frequency | Allowed FSPL | Theoretical Range | Horizon | Recommended Range | Link Margin |
|---|---|---|---|---|---|---|
| Campus PtP 5 GHz | 5800 MHz | 118.60 dB | 3.50 km | 31.93 km | 2.98 km | 16.41 dB |
| Rural Relay 900 MHz | 915 MHz | 114.00 dB | 13.08 km | 37.40 km | 13.08 km | 20.00 dB |
| Urban Mesh 2.4 GHz | 2400 MHz | 93.00 dB | 0.44 km | 24.73 km | 0.31 km | 21.10 dB |
| Warehouse Bridge 5.2 GHz | 5200 MHz | 115.00 dB | 2.58 km | 22.58 km | 2.32 km | 12.92 dB |
Formula Used
1) Equivalent Isotropically Radiated Power
EIRP = TX Power + TX Gain − TX Loss
2) Allowed Free Space Path Loss
Allowed FSPL = TX Power + TX Gain − TX Loss + RX Gain − RX Loss − Misc Loss − Fade Margin − Receiver Sensitivity
3) Theoretical Range from Link Budget
Distance (km) = 10 ^ ((Allowed FSPL − 32.44 − 20 log10(Frequency MHz)) / 20)
4) Radio Horizon
Horizon (km) = 3.57 × (√TX Height + √RX Height)
5) First Fresnel Zone Radius at Midpoint
F1 (m) = 8.657 × √(Distance km / Frequency GHz)
6) Recommended Practical Range
Recommended Range = Minimum(Environment Adjusted Range, Radio Horizon)
The environment profile reduces the pure free-space range to reflect clutter, building density, and less ideal field conditions.
How to Use This Calculator
- Enter the operating frequency in MHz for your radio system.
- Provide transmit power, both antenna gains, and all known feeder or connector losses.
- Enter receiver sensitivity and a suitable fade margin for the reliability target.
- Set antenna heights to estimate radio horizon and practical line-of-sight limits.
- Choose the environment profile that best matches the deployment area.
- Set the desired Fresnel clearance target, often 60% for stable links.
- Press Estimate Range to display results above the form.
- Review the metrics, chart, and export the summary using CSV or PDF.
FAQs
1) What does this calculator estimate?
It estimates theoretical radio range, practical deployment distance, radio horizon, received signal level, Fresnel zone size, and link margin from a basic wireless link budget.
2) Why is practical range lower than theoretical range?
Practical range is reduced by the selected environment profile and may also be limited by radio horizon. Real deployments face clutter, reflections, weather, and alignment losses.
3) What is receiver sensitivity?
Receiver sensitivity is the weakest signal level your radio can decode at a chosen data rate. Lower sensitivity values require more received power.
4) Why is fade margin important?
Fade margin protects the link from temporary losses caused by rain, multipath, foliage, or interference. Higher margin usually means a more stable link.
5) What does the Fresnel clearance value mean?
It shows how much of the first Fresnel zone should remain free from obstacles. Better clearance generally improves throughput and lowers fading risk.
6) Does this replace a site survey?
No. It is a planning tool. Terrain, building materials, interference, antenna patterns, and legal EIRP limits still require field validation.
7) Can I use it for Wi-Fi, microwave, or private radio links?
Yes. The math fits many line-of-sight and near-line-of-sight systems, as long as you enter realistic gains, losses, sensitivity, and margins.
8) What is the best environment profile to choose?
Choose the profile closest to the actual path. Open is optimistic, suburban is moderate, urban is conservative, and dense urban is the most restrictive.