The present Phra Pathom Chedi was built during the reign of King Rama IV in 1853, under his royal command, the new Chedi was constructed to cover the former Chedi of which the shape was of an upside down bell with a Prang top. It is assumed that the former Chedi was dated back to 539 AD as the upside-down-bell-shaped Chedi has a similar style to the Sanchi Chedi in India, built in the reign of King Asoka. The construction of the new huge Chedi was completed in the reign of King Rama V in 1870 AD. In total, it took 17 years to build.
The completed Chedi became a circular one that covers an upside-down, Lankan style, bell-shaped Chedi. The height from bottom to a top crown is about 120.45 metres, and 233.50 metres diameter at the base.