Just do napkin math and figure out what your max payment can be and then you can tell your loan officer what that max payment should be and they will do the math on the max loan amount. 

If you are doing an extremely light rehab you might be in the $15-30/SF, cosemtic rehab might be from $40-60/SF and a full rehab of interior only might be north of $80/sf - There are SOOO many different variables that these should just be used for back of the napkin calculations to verify if a deal is even worth looking into more.Happy to hop on call and talk in way more detail about renovation cost! 

It's a popular rule that a lot of investors go by as a back of the napkin rule of thumb on whether something would typically make sense as a cash flowing asset or not! 

In fact they are already breaking the lease since there’s a clause about maintaining it in a sanitary condition and this is decidedly not sanitary. 

Doing some back of the napkin math and listings on Redfin right now it doesn’t look like anything listed right now makes sense from an investment perspective.

I I am playing with different scenarios and want a back of the napkin number I will use https://www.omnicalculator.com/collections/real-estate.

I've got stories that would be hard to believe on some of my seller financing deals, contract on a napkin, personal check for a notarized deed, hand shake deals, etc., etc. and a LOT of fun.

My basic, back-of-the-napkin metric is looking for gross annual revenues to equal 10% of purchase price.

A real rough back-of-the-napkin metric I use is if a Colorado property's gross annual STR revenues can equal 10% of the purchase price.

Use $70–$90 per sq. ft. for your napkin math.