How long did the construction of the Eiffel Tower take?

The construction of the Eiffel Tower took 2 years, 2 months and 5 days.

Work began on the foundations in January 1887, after Gustave Eiffel’s company won the project for the 1889 Exposition Universelle in Paris. The tower’s ironwork was completed in March 1889, just in time for the world’s fair celebrating the centenary of the French Revolution.

The project required extraordinary precision. Engineers prepared thousands of drawings for 18,038 separate iron parts, which were assembled with roughly 2.5 million rivets. Although hundreds of workers contributed in workshops and on site, the tower was built remarkably quickly for its scale.

A common mix-up is confusing the construction period with the tower’s public opening. Eiffel formally completed the structure on March 31, 1889, but visitors began entering during the exposition in May.