My company is offering me a straight salary instead of an hourly rate. How can I determine if I'll be better off by taking a straight salary?

Does the straight salary include benefits you didn't have before ?

And if you look over the past couple of years on that job ( if you have that to look at) what was the gross pay with overtime you have been getting.
If this new pay more or less,

Also why are they doing this,
Is your position one that is a salary type position ?