How Long Was a Tyrannosaurus rex? 12.3 m (40.4 ft)

Compared with things you know

About 2.7 times as long as a family car (4.5 m)
About the same length as a city bus (12 m)
About 18% as long as a Boeing 747 jumbo jet (70 m)

Tyrannosaurus rex 12.3 m
Family car 4.5 m
City bus 12 m

Drawn to scale: Family car, 4.5 m long · City bus, 12 m long · Tyrannosaurus rex, 12.3 m long

Tyrannosaurus rex dimensions

Measurement	Metric	Imperial	Source
Length (Sue)	12.3 m	40.4 ft	^[1]^[3]
Height at the hips (Sue)	3.96 m	13 ft	^[1]^[2]
Skull length (largest known skulls)	1.52 m	5 ft 0 in	^[1]

Large Tyrannosaurus rex specimens^[1]^[3]^[4]

Sue (FMNH PR2081), Field Museum, Chicago	12.3–12.8 m (40.4 ft – 42 ft)Published range; Guinness gives 12.5 m
Scotty (RSM P2523.8), Royal Saskatchewan Museum	12–13 m (39.4 ft – 42.7 ft)Reported length

How big Sue is

Sue, at the Field Museum in Chicago, is the best-known adult T. rex. Wikipedia says Sue measured 12.3–12.8 m (40–42 ft) long and 3.66–3.96 m (12–13 ft) tall at the hips, and calls it the most complete specimen. The Field Museum describes Sue as more than 40 feet long and 13 feet tall at the hip. Guinness World Records lists Sue at 12.5 m (41 ft) long and 4 m (13 ft) tall.^[1]^[2]^[3]

Scotty, the other contender

Scotty, found in Saskatchewan, Canada, is reported to be 12–13 m (39–43 ft) long and 4 m (13 ft) tall at the hips. Its femur is 133 cm long, against 132 cm for Sue, and it is often called the largest T. rex found. The gap is small: one scientist argued that a 5% difference is within the margin of error, and another called the two specimens statistically indistinguishable.^[4]

Skull size and completeness

Wikipedia says the largest known T. rex skulls measure up to 1.52 m (5 ft) long. That is a figure for the species' biggest skulls, not for Sue in particular. Length estimates also depend on how much of the animal was found. The Field Museum has 250 of the approximately 380 known bones for Sue, and Guinness describes the skeleton as approximately 90% complete.^[1]^[2]^[3]