How much oil do you put in your lawnmower?

The question is too vague to give an accurate response, 2 cycle engines like chainsaws & snow mobiles take a 2 cycle oil / fuel mixture that varies anywhere from 8,16,32 etc to 1 however if you do an online search of the motor manufacturer & provide the information that is contained on the silver colored metal tag usually riveted near the carburetor on the rear side of the block they can tell you the exact weight (10w30) & quantity to maximize the engines lifespan