You can convert this to the expected value in the way you would a financial outcome. The expected value is value times probability. And then the time aspect is

You can convert this to the expected value in the way you would a financial outcome. The expected value is value times probability. And then the time aspect is just discounting future value back to today, like you would a cashflow. Your impulsiveness is then how much you discount tomorrow vs today. (Expectancy * value)*(impulsiveness)^time This way you can put a number on your impulsiveness probably from 1.001 to 2