Total income or AGI?  If you were a W-2 employee your gross income would be in box 1 of your W-2(s).  Your AGI is on your 2017 tax return:

Your 2017 tax return shows your 2016 Adjusted Gross Income  (AGI)  If you filed a joint return then the AGI is the same for each of you.

Form 1040EZ    line 4

Form 1040A       line 21

Form 1040        line 37

"Total Income", for IRS purposes is: 

• Line 22 of form 1040
• Line 15 of form 1040A
• Line 4 of form 1040EZ

Only on form 1040EZ, are tour "Total Income" and your "Adjusted Gross Income: the same thing.

So, it somewhat depends on why do you need to know your total income.