Expenses or debt service? How do rental esimates work?

[Justin Megna]

I understand that a typical rental analysis takes the monthly rental amount, sets aside 5% for vacancies, estimates 50% for expenses, and then makes sure the remaining 45% pays debt service and leaves a profit.

But I've noticed that mortgage calculators often include insurance and tax payments in their monthly mortgage payment estimates. Aren't insurance and taxes typically considered part of the 50% for expenses rather than the 45% for debt service? So when I'm running rough numbers, should I only apply the principal and interest costs to the 45%? Can I presume insurance, taxes, maintenance, and management costs will be covered by the 50%?

Thanks for the help!

Justin