Cap rate vs cash-on-cash vs DSCR: which one actually matters?

This post compares three numbers: cap rate, cash-on-cash return, DSCR. They all look like “return” metrics. They're not. Each one does a completely different job, and conflating them can lead new investors to the wrong conclusion.

Below is a plain-English guide to what each metric actually tells you, when to use which one, and the negative-leverage trap to check for when borrowing costs are high.

Cap rate vs cash-on-cash vs DSCR — the short answer

Cap rate measures the property's unleveraged return (use it to compare properties). Cash-on-cash return measures the return on YOUR specific cash invested after financing (use it to see what the financing does to your own return). DSCR measures the modeled NOI relative to modeled debt service (some lenders use their own version as one part of underwriting).

Three metrics, three completely different jobs:

• Cap rate — the property's unleveraged annual return. Use it to compare properties against each other; set it beside alternatives like bonds only as context.
• Cash-on-cash return — the return on the cash YOU specifically invest. Use it to understand how the modeled capital stack changes the annual cash return. It does not make the investment decision.
• DSCR — the property's ability to cover its mortgage from operating income. Compare it with the specific lender's written convention; it cannot predict whether a lender will approve the file.

Three metrics, three jobs. Read them together: each one covers a risk the other two leave out. On a cash purchase there is no debt service, so DSCR drops out.

Cap rate — what it actually tells you

Cap rate is the property's earning power as if you owned it free-and-clear. No mortgage, no financing, no leverage. Just rent in, expenses out, divided by what you paid. The numerator, NOI, depends on every rent and expense assumption, so verify it line by line.

Why it matters: of these three, cap rate is the only one that strips out financing. Two investors looking at the same property with different down payments and different interest rates will get different cash-on-cash numbers, but the cap rate is identical. That makes cap rate the right metric for comparing properties to each other, and a starting point, though not an apples-to-apples one, for setting real estate beside other asset classes (Treasuries, dividend stocks, REITs).

A reference point, not a rule: set the cap rate beside the yield on a lower-risk alternative such as the 10-year Treasury. If Treasuries pay 4.5% and you're buying at a 4% cap, you're taking on property risk and work for less current yield than the Treasury pays, so the case rests on rent growth or appreciation you would need to support with evidence. Liquidity, leverage, taxes, and workload all differ, so treat the comparison as context.

Where it breaks: cap rate ignores financing entirely. Take a 6% cap rate with a 75% loan on a 30-year schedule. At a 4% rate, the annual payments come to about 4.3% of the price, so the loan leaves a spread and lifts the cash return. At 8%, they come to about 6.6% of the price, more than the 6% the property earns. Cap rate alone can't tell you which of those deals you're looking at.

Cash-on-cash — what it actually tells you

Cash-on-cash measures the return on the cash you specifically invested, after the lender takes their cut. If you put $60,000 into a deal and it produces $5,000 of cash flow per year, that's an 8.3% CoC.

Why it matters: this is the metric that shows what your financing does to your own return. Cap rate doesn't care about your down payment. Cash-on-cash does. CoC tells you whether the leverage you're using is helping or hurting.

The benchmark rule: there is no universal cash-on-cash band. Set your own required return, then compare the result with verified alternatives: if an insured savings account or a Treasury pays close to the rental's CoC, the rental needs to offer something extra under an explicitly sourced scenario, while any tax outcome remains taxpayer-specific.

Where it breaks: CoC doesn't account for principal paydown (your mortgage balance is dropping monthly — real equity being built), a separately sourced appreciation scenario, or taxpayer-specific tax effects. For a broader view, pair CoC with explicitly stated scenarios and keep current operating cash flow distinct from projected value and tax outcomes.

DSCR — what it actually tells you

DSCR (Debt Service Coverage Ratio) measures whether the property can cover its own mortgage payments from operating income alone. A DSCR of 1.25 means the property earns $1.25 of NOI for every $1.00 of mortgage payment.

Why it matters: DSCR is a primary coverage metric in many commercial and non-QM DSCR programs. Those programs often use property coverage instead of personal DTI as the main ratio, while still applying their own borrower, credit, reserve, and property-eligibility requirements, plus appraisal and insurance conditions. Credit to buy or maintain a rental the owner doesn't live in is business-purpose credit, which Regulation Z does not cover.

The benchmark rule: there is no market-wide approval threshold. Even one lender's minimum can vary: Fannie Mae's multifamily guide sets its DSCR requirements by underwriting tier and computes debt service at the note rate or a floor rate, whichever is higher. Ask the lender for its current formula, accepted rent evidence, payment components, rounding, minimum, and pricing tiers. Use a separate, more conservative operating DSCR for your own risk decision.

Where it breaks: DSCR tells you nothing about return. A property could have high modeled DSCR and low modeled CoC because of a large equity contribution. DSCR is one financing input, not a return metric or approval promise.

A negative-leverage scenario

Negative leverage can occur when the effective cost of borrowing exceeds the property's modeled unlevered operating yield.

For example, hold the property assumptions constant and compare a lower-rate scenario with a higher-rate scenario. When financing cost rises above the modeled property yield, debt service can reduce cash-on-cash return. Fees, amortization, leverage, reserves, and timing also matter, so do not infer the outcome from two headline percentages alone.

How to spot it: compare your cap rate with your loan constant (annual debt service ÷ loan amount), not just the note rate. If the loan constant exceeds the cap rate, debt lowers your cash-on-cash return below the cap rate. An upside value scenario, principal paydown, or a taxpayer-specific tax outcome does not erase a current operating shortfall; model each separately and decide whether you can carry the downside.

Side-by-side comparison

So which one matters most?

None is universally first. Read the three together and keep their inputs, formulas, and limitations visible.

Cap rate omits financing, cash-on-cash depends on entered equity and cash-flow assumptions, and DSCR depends on the chosen NOI and debt- service convention. None proves fair value, future performance, bankability, or suitability.

All three numbers live next to each other in TrueCap's main analyzer. Pro adds the 10-year cash-flow and equity projection, the sensitivity grid, and the Offer Ceiling: the highest price that still meets your targets. Run a real deal.