How tall is the Leaning Tower of Pisa?

How tall is the Leaning Tower of Pisa?

This site lists the Leaning Tower of Pisa at 56.86 m (186 ft 7 in). If that seems oddly specific, it is because the tower has no single height. A building that tilts by almost four degrees has a top that is lower on one side than the other, and different organizations measure from different points. The three figures you will meet most often are:

The gap between the low and high sides is only about 80 cm, but the official figure from the Opera della Primaziale Pisana, the body that has managed the cathedral complex since the Middle Ages, is notably higher at 58.36 m. The Opera does not explain its measuring point; differences of this size usually come from measuring from the foundation level or from the highest point of the bell chamber rather than from today's ground level. Whichever number you choose, the tower is roughly the height of an 18 to 19 story building, and one of the most famous short structures in the world. You can see how it compares with skyscrapers and other monuments in the 3D height comparison tool.

Base, weight and structure

The tower is a hollow cylinder of white and grey marble. Its base has an outer diameter of 15.48 m, an inner diameter of 7.37 m and walls about 2.44 m thick at ground level. The Opera's official figures describe a monument built from 29,424 dressed stones covering 7,735 m² of surface, with 207 capitals on its arcaded galleries. It weighs about 14,453 tonnes according to the Opera; other references give between 14,500 and 14,700 tonnes.

Architecturally it has eight levels: a ground floor of blind arcades, six floors of open galleries, and the bell chamber at the top. The bell chamber holds seven bells, one for each note of the musical scale. The largest was cast in 1655 and weighs about 3.5 tonnes. The tower was never intended as a fortification; it is simply the campanile, or bell tower, of Pisa Cathedral, and it stands behind the cathedral apse on the Piazza del Duomo, the square often called the Piazza dei Miracoli.

Two hundred years of building a tilting tower

First phase (1173 to 1178)

The foundations were laid on 9 August 1173. The Opera cites the 16th-century biographer Giorgio Vasari, who credited Guglielmo and the sculptor Bonanno with laying them, and who wrote that the tower began to lean before it was halfway up. Modern accounts put the start of the tilt at 1178, when only the second floor had been built.

The cause was the ground. The tower stands on a shallow foundation, only about 3 m deep, over layers of soft clay, sand and silt left by ancient river channels. The soil under the south side was more compressible than under the north, so the tower sank unevenly almost as soon as its weight began to build.

A century-long pause

Work stopped soon afterward, largely because Pisa was repeatedly at war with Genoa, Lucca and Florence. That interruption turned out to be the tower's salvation. During roughly a hundred years of inactivity, the clay beneath it consolidated under the existing load and became stronger. Engineers agree that had the builders continued without a break, the tower would almost certainly have collapsed during construction.

Second phase and the bell chamber (1272 to 1372)

When work resumed in 1272, the builders tried to correct the tilt by making the upper floors slightly taller on the low side. The result is that the tower is not straight but gently curved, like a banana, as successive masons kept adjusting toward vertical. The seventh floor was completed in 1319, and the bell chamber was added in 1372, nearly 200 years after the foundations were laid. Its builder is usually identified as Tommaso di Andrea Pisano.

How far does it lean, and how has the lean changed?

The tilt has never been constant. It grew slowly for centuries, accelerated in the 19th and 20th centuries, and was then partly reversed by engineers at the end of the 20th century.

Note that the Opera's own fact sheet still states an inclination of about 5.115 degrees, which does not match the post-restoration figures published elsewhere. Most recent engineering sources, and Guinness World Records, use roughly 3.97 degrees.

A tilt of 3.97 degrees means that the top of the tower overhangs the base by about 3.9 m. That is less than the height of a typical one-story house, yet it is enough to make the tower look as though it is falling, especially when seen alongside the vertical cathedral and baptistery.

Saving the tower: the 1990 to 2001 stabilization

By the late 1980s the lean was still increasing every year, and the collapse of the bell tower of Pavia in 1989 made the danger impossible to ignore. On 7 January 1990 the tower was closed to visitors. In March 1990 the Italian government appointed an international committee of 14 experts; among them was the British geotechnical engineer John Burland, who worked on the project for about eleven years.

The committee rejected the idea of strengthening the soil on the south side by grouting or underpinning, judging that any disturbance to that side could trigger collapse. The work instead proceeded in stages:

1. Temporary counterweight. About 900 tonnes of lead ingots were stacked around the north side of the foundation to hold the tower still while a permanent fix was designed.
2. Safety cables. Steel cables were attached to the third floor and anchored some distance away, ready to restrain the tower if anything went wrong.
3. Soil extraction. Using inclined drills, engineers removed small amounts of soil from beneath the raised north side, about 38 m³ (some 70 tonnes) in total. As the ground closed into the voids, the north side settled slightly and the tower rotated back toward vertical.

The aim was never to straighten the tower, which would have destroyed its identity and its value as a tourist attraction. The committee's goal was to reduce the inclination by about 10 percent. In the end the top moved back by roughly 45 cm, returning the tower to approximately the position it had in 1838. It reopened on 15 December 2001. Monitoring in 2008 found that the tower had stopped moving for the first time in its recorded history, and engineers said it should remain stable for at least 200 years.

The Leaning Tower compared with other landmarks

At around 56 to 57 m, the tower is modest by modern standards. Its fame comes from the lean, not the height.

Rome's Colosseum, another of Italy's most visited monuments, is about 9 m lower than the tower. The Statue of Liberty is about 1.6 times as tall, and Big Ben in London is about 1.7 times as tall. You can see these side by side on the landmarks hub.

Is it the world's most tilted tower?

It is the most famous, but not necessarily the most tilted. The church tower of Suurhusen in northern Germany and the bell tower of the Oberkirche in Bad Frankenhausen have both challenged Pisa for the title of most lopsided tower, with leans of more than five degrees at various points. Pisa is, however, by far the tallest and heaviest of the well-known leaning towers.

Galileo and the tower's height

The tower's height also features in one of science's best-known stories. According to Vincenzo Viviani, Galileo's pupil and first biographer, Galileo dropped balls of different weights from the top of the tower to show that they fall at the same rate, contradicting Aristotle. Galileo was born in Pisa and taught at its university, but he never described the demonstration himself, and historians treat it as a possible thought experiment rather than a documented event. Either way, a drop of about 56 m from the gallery would take a little under 3.4 seconds in a vacuum, enough time for spectators to see whether the balls landed together.

Climbing the Leaning Tower

Visiting the tower is tightly controlled to protect both the structure and visitors. The Opera's visitor rules include:

• Timed, limited tickets. Entry is for a specific time slot, and numbers are capped. Tickets go on sale up to 15 days in advance, and the on-site ticket office closes 30 minutes before the monuments close.
• Age limit. Children who will not have turned 8 by the end of the current year cannot go up. In 2026 that means children born in 2019 or later. Older children need their own paid ticket, a paying adult and ID showing their age.
• No bags. All handbags and luggage must be left at the free cloakroom, and visitors are asked to arrive 15 minutes before their slot.
• Hours. Opening times change through the year. In autumn 2026 the tower opens at 9:00 and closes between 18:00 and 20:00, with last entry 30 minutes before closing. In summer it stays open until 22:00 on certain nights.

The climb itself follows a spiral staircase inside the thick outer wall. The Opera counts 273 steps; other sources give 294 or 296, depending on which stair is used. Because the staircase winds around a tilted cylinder, you can feel yourself being pushed toward the outer wall on one side of each turn and toward the inner wall on the other, one of the most unusual sensations of any monument climb in Europe.

A short tower with an outsized reputation

Measured in meters, the Leaning Tower of Pisa is one of the smaller structures in this site's catalog: a modern 828 m Burj Khalifa is more than 14 times as tall. But few buildings have done more to teach the public about soil mechanics, measurement and engineering judgment. Its height depends on which side you measure, its lean depends on which decade you ask about, and its survival depended on a century-long pause in construction and a decade of careful digging. To convert any of the figures above between meters and feet, use the height converter.