The base power ranges from 30-70. Despite the move showing as Normal type in-game, its type can only be one of the 16 other types but not Normal. Hidden Power receives STAB if the user's type matches the type given to Hidden Power.
So depending on the Hidden Power type, IV/EV spread, and if it will obtain STAB or not its power will vary.
In addition to your comment, like I said it varies. So you would need a neutral subject to test it and some super effective subjects and resisting subjects also.
DB page on Hidden Power