Borrowers are not allowed to complete any of the work themselves as sweat equity.Loan to Value Calculations:The original principal amount of the mortgage may not exceed Fannie Mae’s maximum allowable mortgage amount for a conventional first mortgage.Purchase: For a purchase money transaction, the LTV is determined by dividing the loan amount by the lesser of the “as completed” appraised value of the property or the sum of the purchase price of the property and the total rehabilitation costs.Refinance Transactions: For a refinance transaction, the LTV is determined by dividing the original loan amount by the “as completed” appraised value of the property.Eligible Renovation:There are no required improvements or restrictions on the types of repairs allowed.

And using the 135 and 400 as the dividing lines.

So you take the "total rent" from all units and divide by the ARV.

Divide by 2 for the both of you.  

Take the few extra hours it may take to originate the bank loan and divide it by the added finance charges and its normally more than most borrowers time is worth.

They divide the investment strategies into three categories: normal, aggressive, passive.- These categories are based on cash on cash ROI.

The DSCR ratio is calculated by taking the rental amount (either from a lease or the 1007 page of an appraisal) divided by the new monthly PITI mortgage.

On the house hack, you can divide common expenses by square footage or bedrooms, whichever is more advantageous. 

Divide the price of those units by the sqft, and you’ll get price per sqft.

Then divide that cost by the amount of time between now and then and that's how much you should be putting aside for Capex.For general maintenance, the age and condition of the building will play into that.