I never would have guessed that the three puffins were so different in size. It helped to see the difference in size—so I decided to make the graphic below so you could see for yourself.
Atlantic Puffins are about 10 to 11 1/2 inches (25-29 cm)
Horned Puffins are bigger by 5 inches — 15 inches tall (38 cm)
And the Tufted Puffins are the biggest puffins at 16 inches tall (44 cm)