The debt service coverage ratio is one number, and it decides the entire loan. Most explanations skip the arithmetic, so here it is with real figures.
The formula
DSCR = gross monthly rent divided by total monthly payment
Total monthly payment means principal, interest, property taxes, insurance and any HOA dues. Lenders call it PITIA. It does not include maintenance, management or vacancy, which matters because your actual cash flow will be worse than your DSCR suggests.
A ratio of 1.0 means the property exactly covers its own debt. Above 1.0 there is margin. Below 1.0 there is a shortfall.
A worked example
Take a Long Beach duplex at $880,000 with 25% down.
Both units rent for $2,400, so gross monthly rent is $4,800.
DSCR = 4,800 divided by 5,519 = 0.87
That does not qualify. Most lenders want 1.0 minimum. The property is $719 a month short of covering itself.
Four levers, and what each one does
More down payment
Go from 25% to 35% and the loan drops to $572,000. Principal and interest falls to about $3,902, so the total payment becomes $4,919.
DSCR = 4,800 / 4,919 = 0.98
Better, still short. Another $80,000 of down payment bought 0.11 of ratio. This lever works but it is expensive.
Higher rents
If the units are under market and comparable duplexes rent for $2,750, gross rent becomes $5,500 against the original $5,519 payment.
DSCR = 5,500 / 5,519 = 1.00
Just qualifying, at the original 25% down. This is why the rent roll matters more than almost anything else, and why buying a building with below-market sitting tenants is a financing problem as well as a returns problem. Under AB 1482 you cannot simply raise them.
A lower rate, or points
Buying the rate down to 6.75% drops principal and interest to roughly $4,281, making the payment $5,298.
DSCR = 4,800 / 5,298 = 0.91
Half a point of rate bought 0.04 of ratio. Usually the weakest lever unless you are very close to the line.
More units
This is the one people underuse. A $1,170,000 fourplex at 25% down means a $877,500 loan, roughly $5,986 principal and interest, plus $1,073 taxes and $280 insurance for a payment near $7,339.
Four units at $2,200 each is $8,800 of gross rent.
DSCR = 8,800 / 7,339 = 1.20
A property costing $290,000 more clears the ratio comfortably while the duplex fails. Combined rent from more units beats one lease, every time. This is the entire reason small multifamily pencils where single family rentals do not.
What lenders look for
Reserves matter too. Expect to show three to twelve months of payments in the bank depending on your credit and ratio.
What is not in the calculation
Your income. Your job. Your tax returns. Your personal debt-to-income.
That is the point of the product. If your returns understate you because you write off aggressively, or you have passed the ten property conventional limit, DSCR is often the only path. You also get LLC closings and no cap on financed properties.
The cost is rate, generally 1 to 2 points above conventional investment pricing.
The market matters more than the spreadsheet
A 1.05 ratio in a market with 8% vacancy is fragile. Two empty months erase the margin.
The same 1.05 in Long Beach at 3.9% vacancy, or San Luis Obispo County at 3.5%, behaves very differently. Tight vacancy is what makes a thin ratio survivable, and it is why I spend more time on where a property is than on where the ratio lands.
Send me a deal
Address, current rents, and how much you want to put down. I will run the actual ratio, model the down payment scenarios, and tell you which lender fits. Usually the same day.
About the numbers in this article
Any interest rates, monthly payments, down payment figures and repayment terms shown above are hypothetical examples for illustration only. They are not an offer to lend, not a rate quote, and not a commitment. No rate shown is locked or available on request.
The annual percentage rate will be higher than the note rate, because APR reflects financing costs in addition to interest. Both the rate and the APR you are offered depend on your credit score, loan amount, down payment, occupancy, property type, loan term and current market pricing, and will differ from any example here.
Payment examples show principal, interest, taxes and insurance. Your actual payment may be higher once mortgage insurance, HOA dues, flood insurance or other charges apply. Repayment terms shown are 30-year fixed unless stated otherwise.
All financing is subject to credit approval, income and asset verification, and a satisfactory appraisal. Programs, rates and terms are subject to change without notice, and not all products are available to all borrowers.
Ryan Van Til, NMLS #2732776. Pacific Trust Mortgage, NMLS #2573894. Licensed by the California Department of Real Estate. Equal Housing Opportunity. Your binding terms are those disclosed on your Loan Estimate and Closing Disclosure.