Profit factor

A performance indicator relating to the amount of profit per unit of risk, with values greater than one indicating a profitable system. 

If you risk 0.5% per position with a Profit Factor of 2, you will be risking 0.5% of your capital to potentially gain 1%. If you enter a trade with a Profit Factor of 3, the same logic applies except that you will be risking 0.5% of your capital to potentially gain 1.5%.