How high does a hill have to be before you can call it a mountain?

Question

How high does a hill have to be before you can call it a mountain?

Answer 1

A hill usually has to have a definitive summit of at least 2000 feet in elevation to become a mountain.

Answer 2

There is no actual limit from which a hill becomes a mountain. It is however, generally accepted that a "hill" is a "mountain" when there is a definable summit, accompanied by a steep incline/decline. The incline/decline tends to be sharp and rough, rather than the smooth slope of a hill. The "mountain" must also be able to rest higher than the nearby area so you can clearly see the flatlands beneath you.