How big is Big Ben (Elizabeth Tower)?
Big Ben (Elizabeth Tower): 96 m (315 ft). Measured as height — tower height.
Source: Wikipedia — Big Ben
Where it sits
Among the 23 buildings & towers on this page Big Ben (Elizabeth Tower) ranks 20th from the top by size. The largest in the group is Burj Khalifa at 828 m, which is 8.63× the size of Big Ben (Elizabeth Tower), while the smallest, Christ the Redeemer, is 30 m.
Stand an adult of 1.7 m beside it and the ratio is 56.5×: you would need 56 people stacked head to foot to match its size.
In everyday distances
It fits inside a football pitch 1.1 times over — a pitch is about 105 m and Big Ben (Elizabeth Tower) is only 96 m.
Walking at an easy 1.4 m/s you cover 96 m in 69 seconds. A jet at 900 km/h covers it in 384 milliseconds.
Next to its neighbours in size
The nearest thing larger than it in this collection is Saturn V at 111 m (363 ft), 1.15× the size. Both figures are the same kind of measurement, so the gap is a fair one.
The nearest thing smaller is Statue of Liberty at 93 m (305 ft), so Big Ben (Elizabeth Tower) is 1.03× as big as it. They sit in the same group.
Against fixed yardsticks
Against three fixed yardsticks — Eiffel Tower (330 m) is 3.44× the size of Big Ben (Elizabeth Tower); Big Ben (Elizabeth Tower) is 3.21× the size of blue whale (29.9 m); Earth (12,742 km) is 132,729× the size of Big Ben (Elizabeth Tower).
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 Big Ben (Elizabeth Tower)?
96 m (315 ft), measured as height: tower height.
Where does Big Ben (Elizabeth Tower) rank among buildings & towers?
Number 20 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?
Saturn V, at 111 m, is 1.15× the size.
What is the next size down?
Statue of Liberty, at 93 m, is 1.03× smaller.
How reliable is the figure?
It is taken from the cited Wikipedia article and states its basis (tower height). Values are rounded, and where individuals differ the figure is a representative one, so expect small differences from other sources.