Best scholarly estimate

Photo from Wikimedia Commons
Pharos Lighthouse of Alexandria
One of the Seven Wonders of the Ancient World, guiding ships for 1,500 years/Historical
The Lighthouse of Alexandria (Pharos) was built between 280 and 247 BC on Pharos island in the harbor of Alexandria, Egypt. Ancient sources describe it as approximately 100-130 m tall (estimates vary), making it one of the tallest structures in the ancient world. The lighthouse had three stages: a square base, an octagonal middle section, and a cylindrical top housing the fire and mirror system that could be seen from 47 km away. It stood for roughly 1,500 years before being progressively destroyed by earthquakes between 956 and 1323 AD.
Measurements
Square base stage
First (square) stage
Second (octagonal) stage
Visible from 47 km at sea
Limestone and granite blocks