I own 1.75 acres in southern Oregon that I want to develop into approximately 40,000 SF of self storage.Anyone have any basic "rule of thumb" or "cheat sheet" operating expense formulas that I can use for a proforma? 

Is that the formula that's supposed to work?  

Is there a formula that you use to estimate these?

My purchase has to fit that formula.

I live in JACKSONVILLE area and it’s not easy to find a property that will bring you 10% straight cash flow even with out all the formulas associated with a good deal.

If you don't have the extra capital to withstand those headaches then it might be best to find a tenant that leases on an absolute NNN basis.There are a lot of options to look at and its not a one size fits all formula like a lot will lead you to believe.

The capital required to attain a certain surplus cash flow is a function of:1) Property profitability (net cap rate after expenses)2) Leverage (debt percentage)3) Cost of capital (principal+interest percent of purchase price).I derive the following formula.

.- Motivated Sellers ( How to tell if a seller is motivated)- Determining ARV (comps, MLS, Redfin ETC)- Formula for rentals (since this is buy n hold)- Estimating rehab ( might want to hire a GC for like $50 bc this is really hard to evaluate in the beginning)- Purchase Contract- Assignment Contract- Investor Friendly Title companies in your area- How to create a buyers list (networking at local meet ups/REIAs, posting on Craigslist, calling FSBO, Bandit signs ETC)I think that should get you started.

That's a quick and dirty formula we run on properties to decide in 5 minutes if its worth taking a closer look at or moving on.

Well if you are using the 50% suggestion ( I refuse to call it a rule) and he is using actual numbers, then I am inclined to believe your partners numbers over a quick and dirty formula.