How big is RMS Titanic?
RMS Titanic: 269 m (883 ft). Measured as length — overall length.
Source: Wikipedia — Titanic
Where it sits
Among the 14 vehicles & ships on this page RMS Titanic ranks 5th from the top by size. The largest in the group is Emma Maersk at 397 m, which is 1.48× the size of RMS Titanic, while the smallest, Tesla Model 3, is 4.69 m.
Stand an adult of 1.7 m beside it and the ratio is 158×: you would need 158 people stacked head to foot to match its size.
In everyday distances
A football pitch is about 105 m long. RMS Titanic is 2.56× that, which puts it at 2.6 pitch lengths from end to end.
Walking at an easy 1.4 m/s you cover 269 m in 3.2 minutes. A jet at 900 km/h covers it in 1.1 seconds.
Next to its neighbours in size
The nearest thing larger than it in this collection is the Shard at 310 m (1,016 ft), 1.15× the size. Note the two figures are not the same measurement: for RMS Titanic it is length, for the Shard it is height.
The nearest thing smaller is Space Needle at 184 m (604 ft), so RMS Titanic is 1.46× as big as it. They come from different groups — buildings & towers against vehicles & ships — which is what makes the pairing interesting.
Against fixed yardsticks
Against three fixed yardsticks — Eiffel Tower (330 m) is 1.23× the size of RMS Titanic; RMS Titanic is 9× the size of blue whale (29.9 m); Earth (12,742 km) is 47,350× the size of RMS Titanic.
How this figure was taken
Vehicles are listed by overall length. Rockets are the exception and are given as full stack height standing on the pad. Everything is drawn standing upright so one scale holds.
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 RMS Titanic?
269 m (883 ft), measured as length: overall length.
Where does the RMS Titanic rank among vehicles & ships?
Number 5 of 14 on this site, from Emma Maersk at 397 m down to Tesla Model 3 at 4.69 m.
What is the next size up?
The Shard, at 310 m, is 1.15× the size.
What is the next size down?
Space Needle, at 184 m, is 1.46× smaller.
How reliable is the figure?
It is taken from the cited Wikipedia article and states its basis (overall length). Values are rounded, and where individuals differ the figure is a representative one, so expect small differences from other sources.