How big is One World Trade Center?
One World Trade Center: 541 m (1,776 ft). Measured as height — height to the tip of the spire (1,776 ft).
Source: Wikipedia — One World Trade Center
Where it sits
Among the 23 buildings & towers on this page One World Trade Center ranks 8th from the top by size. The largest in the group is Burj Khalifa at 828 m, which is 1.53× the size of One World Trade Center, while the smallest, Christ the Redeemer, is 30 m.
Stand an adult of 1.7 m beside it and the ratio is 318×: you would need 318 people stacked head to foot to match its size.
In everyday distances
A football pitch is about 105 m long. One World Trade Center is 5.16× that, which puts it at 5.2 pitch lengths from end to end.
Walking at an easy 1.4 m/s you cover 541 m in 6.4 minutes. A jet at 900 km/h covers it in 2.2 seconds.
Next to its neighbours in size
The nearest thing larger than it in this collection is CN Tower at 553 m (1,815 ft), 1.02× the size. Both figures are the same kind of measurement, so the gap is a fair one.
The nearest thing smaller is Taipei 101 at 508 m (1,667 ft), so One World Trade Center is 1.07× as big as it. They sit in the same group.
Against fixed yardsticks
Against three fixed yardsticks — One World Trade Center is 1.64× the size of Eiffel Tower (330 m); One World Trade Center is 18.1× the size of blue whale (29.9 m); Earth (12,742 km) is 23,540× the size of One World Trade Center.
How this figure was taken
Building heights depend on the rule used: architectural height counts spires but not antennas, tip height counts everything. The basis is named with each figure.
How the sizes are taken. Each figure says what it measures — height, length, diameter or elevation — and for which individual or convention. Everything is drawn standing upright on one baseline so a single scale holds, including things that are long rather than tall. Values come from the linked Wikipedia article for each item.
Read the rest — common questions
How big is the One World Trade Center?
541 m (1,776 ft), measured as height: height to the tip of the spire (1,776 ft).
Where does the One World Trade Center rank among buildings & towers?
Number 8 of 23 on this site, from Burj Khalifa at 828 m down to Christ the Redeemer at 30 m.
What is the next size up?
CN Tower, at 553 m, is 1.02× the size.
What is the next size down?
Taipei 101, at 508 m, is 1.07× smaller.
How reliable is the figure?
It is taken from the cited Wikipedia article and states its basis (height to the tip of the spire (1,776 ft)). Values are rounded, and where individuals differ the figure is a representative one, so expect small differences from other sources.