incalculable

adjective3

1. •
   Impossible to calculate.
2. •
   Too much, too vast, or too numerous to enable computation.

   • The loss the National Library suffered from the fire is incalculable.
3. •
   Of a person's mood or character, etc.: impossible to predict.

   • He is incalculable when he's drunk. He can turn from an amiable person into a violent horror in a moment.