Path Loss Calculator
FSPL, Okumura-Hata (150–1500 MHz) and COST-231 Hata (1500–2000 MHz) propagation models.
Valid range: 150–1500 MHz · distance 1–20 km · BS height 30–200 m · UE height 1–10 m
3GPP · ITU-R · Okumura-Hata · COST-231
Path Loss Model Formulas
Free-Space Path Loss (FSPL)
PL = 20·log₁₀(dkm) + 20·log₁₀(fMHz) + 32.44 [dB]
Okumura-Hata Urban (150–1500 MHz)
Lu = 69.55 + 26.16·log f − 13.82·log hb − a(hm) + (44.9 − 6.55·log hb)·log d
a(hm) large city, f ≥ 300 MHz: 3.2·(log 11.75·hm)² − 4.97
Suburban: Lsub = Lu − 2·(log(f/28))² − 5.4 · Rural/Open: Lopen = Lu − 4.78·(log f)² + 18.33·log f − 40.94
COST-231 Hata (1500–2000 MHz)
L = 46.3 + 33.9·log f − 13.82·log hb − a(hm) + (44.9 − 6.55·log hb)·log d + Cm
Cm = 0 dB (medium city / suburban) · Cm = 3 dB (large / metropolitan city)
| Model | Frequency | Distance | BS height |
|---|---|---|---|
| FSPL | Any | Any | N/A |
| Okumura-Hata | 150–1500 MHz | 1–20 km | 30–200 m |
| COST-231 Hata | 1500–2000 MHz | 1–20 km | 30–200 m |
Frequently Asked Questions
What is the difference between FSPL and Okumura-Hata?▾
Free-Space Path Loss (FSPL) models signal propagation in an obstacle-free environment — it is the theoretical minimum loss for a given distance and frequency. Okumura-Hata adds empirical correction factors derived from extensive measurements in Japanese cities, accounting for the additional loss caused by buildings, terrain, and the environment type (urban, suburban, rural). Real measured path loss is always higher than FSPL.
Which model should I use for my LTE network?▾
For 700/800/900 MHz bands (B5, B8, B20, B28) use Okumura-Hata. For 1800 MHz and 2100 MHz bands (B3, B1) use COST-231 Hata. For frequencies above 2 GHz such as 2.6 GHz or 3.5 GHz, neither model is strictly valid — consider ITU-R P.1411 or measurement-based models.
What is excess path loss?▾
Excess path loss is the additional signal attenuation beyond FSPL caused by real-world propagation effects. It is shown in the calculator as "+ X dB excess loss." For example, 20 dB excess loss means the signal is 100× weaker than free space would predict. Urban macro cells typically see 20–40 dB excess loss relative to FSPL.
Why does path loss increase at higher frequencies?▾
FSPL grows with frequency because a fixed-size antenna captures a smaller fraction of the wavefront at higher frequencies (smaller effective aperture). At 1800 MHz the FSPL is about 6 dB higher than at 900 MHz for the same distance, which is why lower-frequency bands like 700 MHz provide much larger coverage areas.