Rental Calculator - Numbers to Use for Maintenance, Vacancy, etc. (Columbus, OH)

[George Young]

I am starting out in the real estate investing world, and am running the numbers for some listings in B and C+ neighborhoods in the Columbus, OH market.  

For the rental calculator, I assumed: 

Maintenance and repair = 5% of rent 

Vacancy = 5% of rent 

Capex = 5% of rent

Management fee = 8% of rent 

Leasing fee = approximately 8% of rent (assuming typical lease lasts 12 months and leasing agent / property manager charges 100% of first month rent) 

Closing cost = 1.5% of home purchase price 

Are these realistic assumptions to make, in particular in B and C+ neighborhoods in the Columbus, OH market?  Any insight is much appreciated. 

Thanks all!