Also found this
info from Desloges Law Group
.5.32 states as follows:
"Total income" as referred to in R133(1)(j)(i) is the total income shown on line 150 of the Notice of Assessment.
To make a long story short, Line 150 is the only relevant number we need, and thankfully no additional calculations are required in filling up the sponsor's Financial Evaluation. If you're like me and math makes your head hurt, you could stop there, but if you really want to understand why this all makes sense, please keep reading.
Line 150 on a person's tax return represents the total of Lines 101-147, representing all potential income sources, such as employment income, business income, rental income, commission income, etc. See a line by line breakdown at
http://www.cra-arc.gc.ca/E/pbg/tf/5006-r/5006-r-15e.pdf
Since self-employed income is captured in lines 135-143 of a person's tax return, it is automatically captured in Line 150 and no separate calculation is needed on our side. Something important to note is that in lines 135-143, only the NET self-employed income goes toward Line 150. This means that any business deductions the person claimed have already been taken out and only the surplus goes toward Line 150.
Deductions such as RRSP contributions are reflected in Lines 206 onward, and therefore do not have to be included in "Total Income".
So to summarize, the amount which is relevant in calculating Minimum Necessary Income is limited to "Total Income" which is fully represented and pre-calculated by simply using the figure from Line 150 of the person's Notice of Assessment.