Maximum Hit Points
From FOnline: 2238 Wiki
The base maximum hit points formula is 15+Strenght+(2*Endurance).
Besides, you will get more hit points when you go up a level : The formula of hit points per level is (Endurance/2)+2. As the number of hit points per level is rounded to the inferior, it is advised to have an even number in Endurance (2, 4, 6, 8, 10).
For more informations about hit points check out the Hit Point article.