?? Is there a certain way to do this or something?

Be more specific, what level? Combat? if you talk about combat you can use Tip.it's combat calculator

If you're talking about your combat level... you don't have to figure it out as it's already shown.

 

 

 

Under the first tap (the two crossed swords), then above the attack style buttons, your combat level is clearly visible.

http://www.tip.it/runescape/?page=combat_calc.htm

Under the first tap (the two crossed swords), then above the attack style buttons, your combat level is clearly visible.