Working backwards
The game never shows IVs directly. Enter the numbers you see on the summary screen, set the level and nature — and the calculator checks which IVs from 0 to 31 produce exactly that result. The higher the level, the narrower the range; at level 5 a dozen or more different IVs give the same number. More in the IVs, EVs and natures guide; the stat calculator works the other way around.
Pokémon
Pikachu
#025