Should I include income tax when comparing rental properties?

[Nick Akey]

I want to calculate the potential monthly income that I would receive from buying and renting properties.

Example: If the income is $250 a month - should I reduce that number according to my income tax rate?

OR is it standard to just assume that deductions will reduce the taxes to almost nothing?

P.S. I know I can consult a CPA about this, but I'm more curious about whether folks generally reduce their expected income according to income tax, or just assume deductions will cancel it out and don't include it in the estimates.