Coverline Free Real Estate Investment Calculators

Coverline is a set of 20 free calculators for people investing in small rental properties, from single-family homes to small multifamily.

It starts where a lender starts: the DSCR calculator tests whether rent covers the full monthly payment (principal, interest, taxes, insurance and HOA), and the DSCR Max Loan calculator works back from the rent to the largest loan and purchase price a DSCR lender would allow. From there, investors can model rental cash flow after vacancy, management, repairs and CapEx, plus cap rate, cash-on-cash return, debt yield, LTV, refinance break-even, rate buydowns, and full strategies like BRRRR, fix-and-flip, house hacking, short-term rentals and 1031 exchanges.

What makes it useful:
– Underwriter definitions: PITIA, NOI and DSCR are calculated the way lenders define them, so the numbers hold up when you call a lender.
– Private by design: every calculation runs in the browser; nothing typed is sent, stored or logged.
– Free with no signup: no account, trial or email gate, and unlimited runs.
– Plain-English guides explain the math (what a DSCR loan is, how to calculate cap rate, DSCR lenders compared).

There is also a separate set of homebuyer tools (home affordability under the 28/36 rule), and optional paid Excel underwriting templates from $29 for investors who want a full deal model. The calculators can also be embedded on other sites.