It actually depends on a multitude of factors: goal(weight gain, FFM mass gain, losing weight), macronutrient ratios, type and timing of protein, etc.
If you have an average BF%, then 1-1.5g/lb is ideal. Make sure you're not just using whey protein. Use a quick acting protein post-workout, and then a product that contains different types of protein throughout the day. That way, you'll get a "constant" supply of protein throughout the day.