How tall is the London Eye?

How tall is the London Eye?

The London Eye on the South Bank of the Thames is 135 m (443 ft) tall from the ground to the top of its rim, according to its operator. The wheel itself is 120 m (394 ft) in diameter. The difference comes from the hub sitting high on its support structure, which leaves about 15 m of clearance between the bottom of the rim and the ground. At the low point, passengers step into capsules from a platform at the river's edge. Thirty minutes later, at the top, they are 135 m up.

This site uses 135 m as the London Eye's height and 120 m as its width. Here are the key numbers.

Cantilevered from one side: what makes the Eye unusual

Most giant wheels are held by supports on both sides of the hub, like a bicycle wheel between two forks. The London Eye isn't. Its entire weight hangs from a single A-frame on the landward side, angled back over the river walk, with the wheel cantilevered out over the Thames. Engineers at Arup, the structural engineer, and the architects Marks Barfield designed it so that nothing blocks the view on the river side. This is why its operator describes it as the world's largest cantilever observation wheel, a title it still holds even though several taller wheels have since been built.

The structure also works more like a bicycle wheel than an old fairground ride. A slender rim is kept in shape by tensioned cables running to the central hub and spindle. Cables carry loads very efficiently in tension, which lets a 120 m rim stay light enough to be held from just one side.

Capsules outside the rim

On a traditional Ferris wheel the cabins hang below the rim and swing. On the Eye, the 32 egg-shaped glass capsules are mounted on the outside of the rim. Each sits in a ring and is motor-driven to stay level as the wheel turns. That puts passengers outside the structure, so the spokes don't get in the way of the view at any point in the ride. Each capsule weighs about 10 tonnes.

On capacity, the official sources disagree. The operator's history page says up to 25 passengers per capsule, while its current home page says up to 28 guests. The capsules are numbered 1 to 33 because number 13 is left out. Each stands for one of London's 32 boroughs.

From competition entry to permanent landmark

The Eye began as a competition entry. In 1993 the husband-and-wife architects David Marks and Julia Barfield proposed the wheel for a contest seeking a landmark to mark the millennium, run by The Sunday Times and the Architecture Foundation. The architects pressed on with their own scheme, and the operator says they worked through about 100 variations of the structure before settling on the final design. A newspaper-backed "Back the Wheel" campaign followed, and British Airways became the main financial backer.

Lifting a wheel out of the river

The Eye was not built upright. Its rim sections were floated up the Thames and assembled lying flat on temporary platforms in the river. The whole wheel was then pulled up slowly with a strand-jack system at about 2 degrees per hour until it reached 65 degrees, after which it was moved into its final vertical position. A crane tall enough to build a 135 m wheel in place would have been impractical on a crowded riverbank in central London, so the flat-then-lift method solved both the height and the space problem.

Meant to be temporary

The Eye was planned as a temporary millennium attraction that could be dismantled and moved after a few years. It proved so popular, with about 3.5 million riders a year according to the operator, that it became permanent. It has carried a series of sponsor names, including the British Airways London Eye, Coca-Cola London Eye and lastminute.com London Eye, but the original nickname, the Millennium Wheel, has mostly faded.

Reading the numbers: height, diameter and width

Most confusion about the Eye's size comes from mixing up three different measurements, and each one answers a different question.

• 135 m is the height. It runs from ground level to the top of the rim and is the right figure for comparing the Eye with towers, statues and buildings. Imperial sources give it as 443 ft.
• 120 m is the diameter. It measures the wheel alone, rim to rim, and is the figure to use for comparing wheels by size. Converted to feet it is about 394 ft. One official page prints 294 ft, which looks like a typo, because 120 m cannot be 294 ft.
• 120 m is also the width. Because the wheel is a circle, its width seen face-on equals its diameter. That is why this site gives the Eye a width as well as a height. Seen from the South Bank, the Eye is wider than Big Ben is tall, and wider than the Statue of Liberty's total height of 92.99 m.

These distinctions matter when you build comparisons. If you line the Eye up against a skyscraper by diameter, you understate it by 15 m. If you compare it with another wheel by height, the result depends on how high each wheel's hub is mounted. Two wheels of the same diameter can differ in height by several meters simply because one hub is mounted higher above its boarding level than the other, so check which figure a ranking uses before you compare.

The other point to watch is the capsule. Passengers ride in capsules fixed to the outside of the rim, so at the top of the rotation their eye level is close to, but not exactly at, the 135 m figure. For a rough guide, treat the top-of-ride view as being about 130–135 m above the river path, a little below the summit of the Great Pyramid today and well above anything else on that stretch of the Thames apart from the Shard and the City towers.

The world's tallest wheels compared

The London Eye was the tallest observation wheel in the world from 2000 to 2006. It is now fifth among the major wheels.

Every wheel above the Eye is supported on both sides, so its cantilever record still stands. All of them are also far taller than George Ferris's original 1893 wheel at the Chicago world's fair. Sources disagree on that wheel's exact height, but it was well under 100 m.

London Eye versus other landmarks

The 135 m height puts the Eye in an interesting middle position: taller than every historic building around it, but small next to modern skyscrapers. These heights come from this site's landmark data. You can stand them side by side in the 3D height comparison tool.

The Great Pyramid comparison is a neat coincidence. A capsule at the top of the Eye is almost exactly level with the summit of Khufu's pyramid as it stands today. The view across the river to Big Ben is the one most riders remember. At the top of the rotation, the capsule is about 39 m above the tip of the Elizabeth Tower's spire. The Shard, roughly 2.5 km downstream, is the one nearby building that clearly looks down on the Eye.

What you can see from 135 m

The operator says that on a clear day the view stretches up to 40 km. The usual highlights are the Houses of Parliament directly opposite, Buckingham Palace and St James's Park to the west, and St Paul's Cathedral and the City's towers to the east. Ignoring haze and buildings in the way, the distance to the horizon from 135 m works out to around 40 km on flat ground, so the operator's figure matches what simple geometry allows.

Because a full turn takes about 30 minutes, the time spent near the top is short. Simple geometry shows riders are within 15 m of the highest point for only about seven minutes of the half-hour trip. Photographers often aim for a capsule in the late afternoon in winter, when sunset comes early and the city lights up during the second half of the ride.

Riding at human scale

At a rim speed of about 26 cm per second, the wheel moves slower than a casual walk, which is about 1.4 m per second. That's why it usually keeps turning while people board: passengers walk on and off as the capsule passes the platform. For a sense of scale, the 120 m wheel is about 70 times the height of an average British man, and the 135 m top is roughly level with a 40-story building.

Planning a visit

The London Eye operates for most of the year, with hours that vary by season and day. Tickets are timed, and fast-track and private-capsule options are sold. Check the official site for current hours, prices and accessibility information before you go. The nearest stations are Waterloo and, across Westminster Bridge, Westminster. For more structures to compare with the Eye, see our landmarks hub.