Enter the CP and HP from the game, the Stardust on the Power Up button and where you got it to find every possible level and IV combination. The more you enter, the fewer candidates remain.
1. Pick a Pokémon
2. Enter the numbers from the game
Pokémon state (changes the Stardust cost)Appraisal stars (the game's Appraise screen)
3. Possible IVs
Pick a Pokémon and enter its CP to see the possible level and IV combinations here.