What was the size of a stegosaurus?

Stegosaurus was about 30 feet long, 15 feet tall at the top of its highest plates(about 10 feet at the head), and weighed up to 4 tons.

The stegosaurus was about 30ft long and 14ft tall.

Answer2: The stegosaurs were a group of the ornithischians that had large bony blades mounted in a pattern down their back. They walked on all four legs and were about 20 feet [6 m] long, and 8 feet [2.4 m] high at the hips. More recently, it has been thought that the bony back plates served not just as a protection but as part of a cooling system for their body. Hind legs were heavy and elephantine, while front legs were of smaller size, causing the small head to be low to the ground. The tail had long, bony spikes radiating from the end.