The average turtle "runs" about 3 to 4 miles per hour. They walk at a rate of a little over 1 mile per hour. Turtles are much faster in the water than they are on land.
Speed depends on the type of turtle and how old the turtle is. Turtles are usually faster than tortoises, even on land. Sea turtles can barely move on land because of their flipper-like legs, but they move very quickly in the water. A leatherback turtle was clocked as the fastest reptile, going 22 miles per hour when swimming while frightened. Young turtles are much slower than older turtles at both swimming and walking.