How to analyze a short term rental property

[John Armando]

Hello BP,

I live just outside of Boston and am interested in purchasing a short term rental property in the North Conway area (for those not from New England), North Conway is a popular destination, as it is within 30 minutes of 3 large skiing mountains, close to summer hiking, as well as family attractions such as Storyland and Santa's village. In addition the town is fairly well populated, thus there are a number of restaurants, shops, etc. 

I have a pretty well built Excel calculator I use for valuing traditional long term multi-family rentals, but am not sure the best way for determining estimated rental income for a short term rental property, which would be listed on something like VRBO or AirBNB. 

My question is, how can i determine my expected annual and monthly income for a rental property accounting for vacancy, weekend vs. weeklong rentals, peak vs. off-season rates, etc. 

Any help would be greatly appreciated!