How much should I keep in reserve

[Dan Grove]

Hello all, 

I have the opportunity to buy more than one property but wanted to make sure I have enough money in reserve for problems with the rehab, longer time to get a tenant, etc.  I am going to budget money for vacancies, repairs, cap ex, and PM.  On the one hand I want to make sure I have enough money extra available during the initial process in case there are any issues.  On the other, I don't want to hold too much capital back that could be used for other projects if they come along. 

The simple question is, how much money do you hold back for each project as a percentage of the esimated all in cost.  For example, if I estimate a cost for the house plus the rehab of 100K, how much should I keep in the bank just in case?  

Thanks,

Dan