In today’s world, it’s hard to imagine an animal like the Argentinosaurus, which at 39m in length was as long as a 10-storey building is tall. Our largest land animal today is the African elephant, which at 6-7m long would be dwarfed by this giant. If you’ve ever wondered how some of the dinosaurs measured up  in comparison to modern-day objects and animals, you’ll find our handy size guide useful. 

Diplodocus

At 26m in length, Diplodocus may not have been the largest of the sauropods, but it still cut an impressive figure on the prehistoric landscape. This plant-eating giant was just a little shorter than a blue whale, or the equivalent of the width of an Olympic swimming pool. If you’re near Coventry, pop to the Herbert Art Gallery & Museum for a family day out and you’ll see a replica of a Diplodocus skeleton (called Dippy) there until February 2026. 

Apatosaurus

Apatosaurus was only slightly smaller, ranging between 21 and 23m in length. It would just about fit on a tennis court (23.77m), and is comfortably longer than large marine creatures like the whale shark. Its neck alone measured around 6m, which is the same length as a saltwater crocodile. 

Tyrannosaurus rex

At 12m long, T-Rex was a formidable carnivore. Imagine a creature the length of an HGV or a yacht coming after you, equipped with 50-60 teeth the size of a lemonade bottle! And he wasn’t even the largest theropod - Spinosaurus is thought to have been a little longer at 14-18m. 

Triceratops

Triceratops was fairly modest in size for a dinosaur. At 8-9m long, it was around the same length as a reticulated python in today’s animal kingdom. It’s also comparable to a double decker bus. Its horns, meanwhile, could grow to almost a metre long - about the width of the dining table. 

Segnosaurus

This meat-eater was significantly smaller than a tyrannosaur, but you still wouldn’t want to meet one. At 4m long, this theropod from the Late Cretaceous period was about the same length as a car or a white rhino. 

Citipati

At 2.1m in length, this omnivorous dinosaur was about the size of many of the modern world’s larger animals - from small dromedary camels to lions. You could get an idea of Citipati’s size by asking an adult to stretch out their arms.

Velociraptor

This miniature, feathered carnivore was a lot smaller than many people realise. At around 1.8m, it was the same length as a tall human, and stood about as high as a turkey. It would be able to comfortably stretch out on a three-seater sofa or a six-seater dining table. 

Microraptor

As its name suggests, Microraptor was one of the smallest dinosaurs, measuring around 77cm in length. That’s about the height of a standard bedside table or the same length as an ocelot. 

Walk with dinosaurs

To get a flavour of the size of some of the most intriguing dinosaurs - from microraptor to T-Rex - why not book a family fun day out at Dinosaur World Live? This walking with dinosaurs theatre show is aimed at kids and uses puppetry to introduce them to a range of prehistoric beasts. Book your tickets today!