Dinosaur size comparison
How big were dinosaurs next to a person? These sizes come from real specimens, measured nose to tail or to the top of the head from museum skeletons and published papers, with an adult man for scale. Each name opens its own size page with the source and exactly what was measured.
Dinosaurs, smallest to largest
The dinosaurs to scale, smallest to largest, with an adult man in orange.
| Object | Size | vs Adult man |
|---|---|---|
| ArchaeopteryxThe Jurassic feathered dinosaur often called the first bird, measured nose to tail. | 50 cm long | 29% of the size |
| Adult man (US average)An average adult man, for scale. | 1.75 m tall | – |
| VelociraptorA feathered predator from Cretaceous Mongolia, measured nose to tail. | 1.8 m long | about the same |
| Stegosaurus (Sophie, NHM London)Sophie, the most complete Stegosaurus skeleton ever found. Measured nose to tail. | 5.6 m long | 3.2× bigger |
| AnkylosaurusThe armoured dinosaur with a bony tail club, measured nose to tail. | 8 m long | 4.6× bigger |
| TriceratopsThe three-horned plant-eater of Late Cretaceous North America, measured nose to tail. | 9 m long | 5.1× bigger |
| Tyrannosaurus rex (SUE, Field Museum)SUE, one of the largest and most complete T. rex skeletons. Measured snout to tail. | 12.34 m long | 7.1× bigger |
| Giraffatitan (Berlin skeleton)A long-necked sauropod from Jurassic Tanzania, mounted with its head held high. | 13.27 m tall | 7.6× bigger |
| SpinosaurusThe sail-backed river hunter of Cretaceous North Africa, measured nose to tail. | 14 m long | 8× bigger |
| Diplodocus (Dippy, NHM London)Dippy, the Natural History Museum's famous Diplodocus cast, measured head to tail. | 26 m long | 15× bigger |
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