Mental Math - Cap Rate, Value, NOI
does anyone have any shortcut or tricks that they use to calculate any of the above when given 2 of the 3? 

Thanks!

edit: Was asking for mental shortcuts. like if you're in a conversation with someone and 2 of the 3 variables are spoken about
[{"id": "cocjrr0", "text": "Cap Rate is just NOI / Price. \n\nFor fast and loose prices you need rents and expenses. I usually use a multifamily shortcut of Income (average rent * # of units) - Opex (40% of income)= NOI. NOI/ 10% cap rate = a good price for value add property. NOI / 5% cap rate for a new/class A property with market vacancy. If you start looking at a lot of deals in a specific market you'll come up with your own shorcuts.      ", "replies": [{"id": "cockvsl", "text": "sorry should have been more specific. I was asking about mental shortcuts.\n\nFor example, someone gives you in a conversation the purchase price and NOI. What's a quick way to back into the cap rate. Same question if you change which variables you're given.", "replies": [{"id": "codtm4p", "text": "This seems like an odd question? Just divide the NOI by the purchase price?\n\nIf you have 10000 at the noi and 100000 at the pp you can eliminate the 0s? ", "replies": [], "depth": 3}], "depth": 2}], "depth": 1}, {"id": "cockiqu", "text": "Start at 10% and then add or subtract 1% to figure out the approximation.  Just like calculating the tip at a restaurant.", "replies": [{"id": "coclkd2", "text": "I do the same, its worth adding to remember these are all ratios, so going to 5% off 10% is just half NOI or double value.  Its 1+percent so depending how good you are doing division/multiplication of 1.x's in your head you may want to approximate but this holds too for things like reducing/adding to the value too to back into cap.  Ie if you are at 10 cap and something costs 1 mil and you think you need to do 100k of other crap, you are going up 10 percent, so the cap is just now 10/1.1 (or you approximate to just above 9 pretty easy ;) )  \n\nAnyhow I guess thats a long ass way of saying like /u/b6passat I always start at 5 or 10 too then either multiply or add smaller amounts to get near where I want.", "replies": [], "depth": 2}, {"id": "cog7oot", "text": "be careful with this.  Say an NOI is 100k.  at a 6% Cap, building is worth 1.67 million.  At a 5% cap, it's worth 2,000,000.  This rule of thumb works when you're basing off of a 10% cap rate because 1% chagne is 10% of your original cap rate.  The further you get from a 10% cap, the less accurate it is.    ", "replies": [], "depth": 2}], "depth": 1}, {"id": "cocuvef", "text": "IRV.  It's just algebra. The more experience you have dealing with them, the more second nature it becomes.", "replies": [], "depth": 1}, {"id": "cof9ipp", "text": "When I know the income, instead of dividing by cap rate, I multiply by the inverse. So 150,000 no I at a 9 cap would be multiply by 11, roughly 1.65 million. Multiply by 12 and that's an 8.33 cap. 13 is about a 7.7 cap.  So if you need to figure at an 8 cap its about halfway between 12 and 13. \n\nWorks for me and I use it all the time. \n", "replies": [{"id": "cofxt5c", "text": "inverse of what? ", "replies": [{"id": "cofy7vm", "text": "Inverse of the cap rate. So if cap rate is 9, I multiply by the inverse which is roughly 11 because 1/.09 =11.1. Its easier to multiply by 11 than to divide by .09 for me. ", "replies": [{"id": "cog5u1j", "text": "ah, got it. very cool/helpful. thanks!", "replies": [], "depth": 4}], "depth": 3}], "depth": 2}], "depth": 1}]