The noun form of broad is breadth, the noun form of long is length, and the noun form of wide is width.
Because of this, some people follow the pattern and say heighth, with a th at the end of the word high. That is not standard English. The correct form is height.
Notice the vowel change with an ei. It is not ie because it does not make the long e sound.
Incorrect: What is your heighth above sea level?
Correct: What is your height above sea level?