Usually, when *too* is used at the end of the clause, [it means 'also' or 'as well'.][1] So, ***also = too*** in that way. 

> *When I've finished painting the bathroom, I'm going to do the kitchen **too/also/as well**.*

The preposition 'to' is entirely different. Don't use it to mean 'too/as well/also' in **any** case. 

*'to'* has many meanings and usage. Refer any dictionary ***<del> too</del> to*** find that!


  [1]: http://www.oxfordlearnersdictionaries.com/definition/english/too?q=too