I started my domain over 10 years ago when people first started going online trying to buy fixer upper houses.

Plus, they handle online rent collection (a necessity if you don't have a property manager!)

For something more robust, tools like Excel or online calculators from financial planning sites might better suit your needs.Your ROI Formula:ROI = (Net Cash Flow ÷ Total Out-of-Pocket Investment) × 100For your scenario:Net Cash Flow = Annual Rental Income - (Mortgage Payment + 401k Loan Payment + Other Expenses)Total Out-of-Pocket Investment = $40,000 cash + $50,000 loan payments over 5 years.I came across a piece in Bloomberg recently discussing creative financing, and they touched on ROI calculations for multiple loans.Personal anecdote: A buddy of mine leveraged a 401k loan for a fourplex.

A safe baseline is 5%–10% for vacancy, with C class properties often leaning toward the higher end due to more transient tenant populations.As for maintenance, the percentages they’re quoting—2% for B class and 7.5% for C class—are on the optimistic side, especially for long-term projections.

Microsoft Excel, and most budget or free online bookkeeping isn't going to cut it in this situation.For the rental properties you own directly, I often tell clients and prospects that a P&L in Microsoft Excel is just fine and a balance sheet is not necessary for tax purposes. 

If you choose an online program, ask how much access you have to the coach.

I am seeing quotes around $120k which would put that cost per square foot around $600 which seems a lot compared to what I have seen/read online The reason your cost per square foot is so high is you still have to add all the things a regular house has but in a smaller space.

In most states they must be published in a local paper which all are online.

Thank for your help Connect with a great property manager or use one of the free online tools to estimate rents.

Do i t to build your online presence, reputation and credibility as a business.