, go ahead and make a copy so you can edit it.
Say you have 2 Dragonites, one at 0% level 25, and one at 100% level 10 (that's the example already entered). Enter the base stats for the species, IVs and level for your Pokemon, and then it will plot what CP each would be at with a candy investment. As you can see from the example, the 100% Dragonite starting at level 10 would have a higher CP than the 0% Dragonite starting at level 25 after investing 92 candies.
I made this to decide which Chansey I will evolve and power up once Blissey is out, and thought others might like it.