Like they said above, there's no formula for how much you'll gain. But I'll tell you if you want to increase your veritcal leap then jumping rope isn't the best way to go about it. You'll make some gains from it but there are a couple things that make it less effective than other methods. For one, a vertical leap is one singular max effort performance so jumping rope 500 times doesn't mimic that very well. You'd be better off doing some activity that requires fewer repetitions but greater intensity per repetition. Second, your quadriceps are going to go through a shorter range of motion during the jump rope than during a vertical jump test. Your calves will get a good workout but the ankle joint is responsible for between 20-40% of the power when it comes to vertical jumps. Most of the power comes from the quads, hamstrings and glutes.