How tall is the CN Tower?

How tall is the CN Tower?

The CN Tower in Toronto stands 553.3 m (1,815 ft) tall, the figure used on this site. The tower's own history page rounds it to 553 m (1,815 ft), and the commonly quoted precise value is 553.33 m (1,815 ft 5 in). Completed in 1975 and opened to the public on 26 June 1976, it was the world's tallest freestanding structure for more than three decades and is still the tallest in the Western Hemisphere.

The tower is a concrete communications and observation tower, not a building, so it is ranked separately from skyscrapers. Its concrete shaft alone rises 335 m (1,100 ft); above that, a steel antenna mast carries it to its full height. You can compare it with the world's tallest buildings and towers in the 3D height comparison tool.

The CN Tower's key levels

The tower has several public levels, each at a different height. The table combines figures from the tower's official pages and published references.

The official site describes The Top as the highest viewing platform in the Western Hemisphere. At around 446.5 m it is higher than the observation decks of One World Trade Center (386.5 m) and Willis Tower (412.4 m).

Building the CN Tower (1973 to 1976)

Why Toronto needed it

The tower takes its name from Canadian National, the railway company that conceived it in 1968. As Toronto's downtown filled with new skyscrapers in the 1960s, the buildings began to block and reflect television and radio signals from existing transmitters, which were not tall enough to broadcast over them. A single, very tall tower solved the problem. The railway also saw it as a showcase for Canadian engineering and a draw for tourists in the redeveloping Railway Lands near the lakefront.

Slipforming the shaft

Crews broke ground on 6 February 1973, removing more than 56 metric tonnes of earth and shale for the foundations, according to the tower's history. More than 1,500 workers spent 40 months on the project.

The shaft was cast using a slipform: a continuous mold that rose slowly on hydraulic jacks while concrete was poured into it around the clock. The form was designed to narrow as it climbed, producing the tapered profile of the hexagonal core and its three curved support legs. By February 1974 the tower was already the tallest structure in Canada. Work on the seven-storey main pod began in August 1974.

Wikipedia's account puts the volume of concrete at about 40,500 m³ and the total mass of the finished structure at about 118,000 tonnes.

Olga and the antenna

The final stage was the steel antenna mast, which needed to be lifted in pieces far above the reach of any crane. The contractors used a Sikorsky S-64 Skycrane helicopter nicknamed Olga. According to the tower's official history, Olga lifted 39 pieces of the antenna into place in March 1975; other accounts give slightly different counts. Using a helicopter saved months of construction time. The final piece was set on 2 April 1975, and on the same day Guinness World Records certified the CN Tower as the world's tallest freestanding structure.

The tower opened to the public on 26 June 1976 at a cost of about CA$63 million.

Records: how long was it the tallest?

Sources describe the end of its world record differently. Burj Khalifa's structure climbed past 553 m in 2007 while it was still under construction, which is the date most references use. The CN Tower's official history says it remained the tallest freestanding structure until Burj Khalifa surpassed it in 2009, the year the Dubai tower was completed. Either way, Toronto held the record for more than 30 years.

In 1995, the American Society of Civil Engineers named the CN Tower one of the Seven Wonders of the Modern World, alongside projects such as the Panama Canal and the Channel Tunnel. The same year, Canadian National sold the tower to the federal Canada Lands Company.

Tower or building? Why One WTC is "tallest" and CN Tower is "taller"

The CN Tower is about 12 m (40 ft) taller than New York's One World Trade Center, yet One WTC is called the tallest building in the Western Hemisphere. The difference is classification.

CTBUH's criteria state that a structure must have at least 50 percent of its height in occupiable floor space to qualify as a building. Telecommunication and observation towers that fail that test are not eligible for its "tallest building" lists. Most of the CN Tower's height is a concrete shaft containing elevators and stairs, with occupiable levels only in the pod and the upper observation level, so it is a tower. Both titles are correct: One WTC is the tallest building and the CN Tower is the tallest freestanding structure on the continent.

The CN Tower compared with other towers and buildings

Tokyo Skytree, the current tallest tower, is about 81 m higher. The CN Tower is a little more than 1.6 times the height of the Eiffel Tower and almost exactly three times the height of Seattle's Space Needle. Compared with Chicago's Willis Tower, it is about 111 m taller at the tip of its antenna, although Willis Tower's own antennas reach 527 m. Browse more towers in the landmarks hub.

Visiting the CN Tower

The tower welcomes more than two million visitors a year and employs more than 500 people year-round. Glass-fronted elevators carry visitors up the outside of the shaft to the main pod.

LookOut and glass floor. The main observation level at 346 m offers indoor and outdoor viewing, and just below it the glass floor at 342 m lets visitors stand directly over a straight drop to the ground. The glass floor was installed in 1994 and replaced with a larger version in 2008, a popular test of nerve.

The Top. A separate elevator climbs 33 storeys from the main observation level to The Top, about 446.5 m above the ground, which the tower describes as the highest viewing platform in the Western Hemisphere. On clear days the view reaches across Lake Ontario.

360 Restaurant. At 351 m, the revolving restaurant completes one rotation every 72 minutes, so diners see the full panorama during a meal.

EdgeWalk. Opened in 2011, EdgeWalk lets participants walk hands-free around the outside of the main pod at 356 m (1,168 ft), attached by a harness to an overhead rail. Guinness World Records certified it on 8 November 2011 as the highest external walk on a building. The whole experience takes about 90 minutes, of which about 30 minutes are spent outside. Participants aged 13 to 17 need a parent or guardian present.

The tower turned 50 in 2026, marking half a century since it opened to the public, and the official site lists anniversary programming through the year. Check opening hours before you go, since some levels close occasionally for maintenance or events.

The stairs: 1,776 steps to the LookOut

The CN Tower also contains what is often described as the world's longest metal staircase, running up the inside of the concrete core. It has 1,776 steps from the ground to the LookOut level at 346 m, a coincidence with the symbolic height in feet of One World Trade Center. The stairs are an emergency route and are not open for regular visits, but the tower opens them a few times a year for charity stair climbs, during which thousands of participants race up the shaft. Strong climbers complete the 346 m vertical in well under 15 minutes; most people take between half an hour and an hour.

The climb is a vivid way to appreciate the tower's scale. The LookOut is only about 62 percent of the way to the tip, yet reaching it means climbing the equivalent of a 110-storey building. The remaining 207 m, from the pod to the top of the antenna, is the mast that Olga lifted into place in 1975.

Seeing across Lake Ontario

The tower's height gives an exceptional field of view over flat southern Ontario. Using the standard horizon formula, an observer at The Top, about 446.5 m up, has a geometric horizon of roughly 75 km; from the LookOut at 346 m it is about 66 km. Niagara Falls lies roughly 70 km to the south across Lake Ontario, close to the edge of that range, which is why the mist above the falls and the skyline of the city of Niagara Falls can sometimes be picked out on exceptionally clear days. The opposite shore of the lake, in New York State, is also visible in good conditions.

In the other direction, the view takes in the whole of the Greater Toronto Area, the Toronto Islands, Billy Bishop Airport just offshore, and the Rogers Centre stadium immediately beside the tower's base. From 342 m on the glass floor, cars on the Gardiner Expressway look like toys.

Lightning, wind and the tower's design

At 553 m, the CN Tower is the highest point for many kilometers around, and lightning strikes it many times each year. Copper grounding strips run down the shaft to rods buried below the foundations, carrying the current safely into the ground; visitors inside the pod are fully protected.

The shaft's Y-shaped plan, a hexagonal core braced by three curved legs, gives it stability against wind from any direction while keeping the footprint compact. Wind loads were one of the main concerns of its designers, because the slender mast and pod present a large target to the strong gusts that come off Lake Ontario.

Putting 553 meters in perspective

• The tower is about 316 times the height of a 175 cm (5′9″) adult.
• About six Statues of Liberty, at 93 m from ground to torch, would reach the tip.
• Burj Khalifa is almost exactly 1.5 times as tall.

Convert any of these figures between meters and feet with the height converter.