Fresnel Zone Calculator
Calculate Fresnel zone radius and clearance requirements for line-of-sight RF links.
Link Parameters
Same unit as total distance
60% clearance recommended for minimal loss
F1 = sqrt(lambda d1 d2 / D)
First Fresnel Zone Radius
5.59 m
18.33 ft at obstacle location
5.59 m
Max at Midpoint
0.0 dB
Est. Diff Loss
Required Clearance
40% F12.24 m (7.3 ft)
60% F13.35 m (11.0 ft)
80% F14.47 m (14.7 ft)
100% F15.59 m (18.3 ft)
Fresnel Zones at Obstacle
| Zone | Radius (m) | Radius (ft) |
|---|---|---|
| F1 | 5.59 | 18.3 |
| F2 | 7.90 | 25.9 |
| F3 | 9.68 | 31.8 |
| F4 | 11.18 | 36.7 |
| F5 | 12.50 | 41.0 |
Path Information
Distance TX to Obstacle500.0 m
Distance Obstacle to RX500.0 m
Wavelength12.49 cm
Your Clearance Height3.35 m (11.0 ft)