This tool calculates accurate CP of the Pokémon (evolved or not) from its IV. Any of these tools can be used to find IV of the Pokémon.
Pokémon
Pokémon Level
ATK IV IV
?
DEF IV
STA (HP) IV
Target Level
Evolve ?
Actual CP -
Actual HP -
Evolved to -
Target (...) CP -
HP -
Stardust Required -
Candy Required -
Max (40) CP -
HP -
Stardust Required -
Candy Required -

Pokémon [lvl] (IV) IV % CP HP Ev Target level Max level = 40
lvl CP HP Stardust Candy CP HP Stardust Candy

Data from this site was saved to another my page Pokemon GO Raid boss CP = if you need find true IV and hidden stats you catch raid boss.
Big thx for great Pokémon GO site: Gamepress Pokémon GO - source JS code was inspired (= stolen) from page Pokémon GO Evolution/CP Calculator. I'm sorry, but I needed this comparison tool.
Created by @3knedle