A person has a mass of 88kg, what is his height on earth?

There's no way to calculate his height using the given information,

unless we were also given his Body Mass Index.

However, I'm going to take a big jump here, and assume that you

meant to ask for his "weight" instead of his "height".

Weight = (mass) x (gravity)

On Earth, the acceleration of gravity is about 9.8m/s².

Weight = (88 kg) x (9.8 m/s²) = 862.4 kg-m/sec² =

862.4 newtons (about 194 pounds)