Every weight, every cut-off, every formula, and the limits of what a grade can tell you. If you disagree with a number here, you can change it in the model and the grade moves with you.
Most deal calculators will not tell you how they score. That makes their output impossible to check, and impossible to disagree with. Every number DealGauge produces is below, in full, including the weights and the cut-offs. If you think a weight is wrong for how you invest, change it in the model and the grade moves with you.
| Factor | Points | Full marks at | Zero at |
|---|---|---|---|
| Monthly cash flow after every expense | 35 | +$250/mo | -$100/mo |
| Cash-on-cash return vs your target | 30 | 8% | 0% |
| Debt coverage (DSCR, after all costs) | 20 | 1.25x | 1.00x |
| Cap rate vs your target | 15 | 6% | 0% |
Each factor scores on a straight line between those two points, so a deal at +$75 a month earns roughly half the cash flow points. Cap rate points are capped at half if monthly cash flow is negative, because a good cap rate on a property that loses money every month is not a good deal.
If you enter a purchase with no loan, the coverage factor does not apply and the remaining three are rescaled to 100.
| Score | Grade | What it means |
|---|---|---|
| 85 to 100 | A | Strong on today's numbers |
| 70 to 84 | B | Solid on today's numbers |
| 55 to 69 | C | Marginal. Thin margins in every direction |
| 40 to 54 | D | Weak |
| Below 40 | F | Does not pay you at this price and rent |
It does not reward appreciation. Appreciation is a hope, not a plan, and a grade that leans on it would flatter every deal in a rising market. The score is built entirely on today's cash position.
It does not see risk. This is the most important limitation on this page. A 1958 property in a county losing population and a 2016 build in a growing metro, with identical price, rent and expenses, receive an identical grade. The grade measures the arithmetic, not the asset. It cannot see the roof, the street, the tenant, the insurability, or how quickly you could sell. Treat it as a screen that tells you what is worth visiting, never as a verdict on whether to buy.
It does not know your market. Every default on the calculator is a national rule of thumb. Your county's tax rate, your insurance quote, and your actual achievable rent will all differ, and all three are fields you can change.
Monthly mortgage payment is the standard amortising payment on the loan amount, which is price minus your down payment, at your rate over your term.
Effective gross income is monthly rent minus vacancy.
Operating expenses are property management, maintenance and capital expenditures, each taken as a percentage of rent, plus property taxes divided by twelve, insurance divided by twelve, and any HOA or other monthly cost.
Net operating income is effective gross income minus operating expenses. It is before the mortgage, by definition.
Monthly cash flow is net operating income minus the mortgage payment.
Total cash invested is your down payment, plus closing costs, plus upfront repairs, plus the lender reserve requirement expressed as months of full PITI, plus your starting operating float. This is the honest denominator. Many calculators divide by the down payment alone, which inflates the return.
Cash-on-cash return is annual cash flow divided by total cash invested.
Cap rate is annual net operating income divided by purchase price. Note that our net operating income already sets aside a capital expenditure reserve, so this figure reads roughly a point below a broker-quoted cap rate on the same property. That is intentional.
DSCR after all costs is annual net operating income divided by annual mortgage payments. This is the honest coverage number.
Lender DSCR is gross monthly rent divided by the full monthly payment including principal, interest, taxes, insurance and HOA. This is how a DSCR lender actually sizes the loan, and most look for roughly 1.20 to 1.25. It reads higher than the honest number, which is why we show both.
Most tools solve for one target. We solve three and report whichever binds first, because the lowest of the three is the only price that satisfies all of them.
Property taxes are treated as a rate against the purchase price rather than a fixed dollar amount, because taxes usually reset to what you paid once the sale closes. That means the tax bill moves as the walk-away price moves, which is the correct behaviour and something most calculators get wrong.
The defaults are widely used rules of thumb: vacancy at 5 to 8 percent of rent, maintenance at 8 to 10 percent, capital expenditures at 8 to 10 percent, and property management at 8 to 10 percent. They are starting points, not truth. Your own numbers should replace them, and the calculator is built so that they can.
There are no reviews on this site. DealGauge is new, and we would rather show you the arithmetic than invent praise for it. That is what this page is for. The paid toolkit carries a 30-day refund, no questions asked, and you keep the files.
General information and educational content only, not investment, tax, or legal advice. Benchmarks are common rules of thumb, not guarantees or projected results. Verify every figure and consult a qualified professional before purchasing any property. Questions: [email protected]