The DSCR Formula: How Lenders Run the Math on a Rental

Lenders calculate the debt service coverage ratio (DSCR) by dividing a rental's monthly income by its full monthly housing payment. On most 1 to 4 unit residential DSCR loans, that means gross rent over PITIA: principal, interest, taxes, insurance and association dues. The result tells the lender how comfortably the rent covers the debt.

The formula

DSCR = monthly gross rent / monthly PITIA

• Principal
• Interest
• Taxes (property taxes, monthly share)
• Insurance (hazard, plus flood if required, monthly share)
• Association dues (HOA), if any

At 1.00x, rent equals the payment. Above 1.00x, there is room left over. Below 1.00x, the rent does not fully cover the payment.

A worked example

Example (illustrative only):

• Rent: $2,800
• Principal and interest: $1,850
• Taxes: $300
• Insurance: $150
• HOA: $100
• PITIA: $2,400

DSCR = $2,800 / $2,400 = about 1.17x.

Note that this calculation does not subtract repairs, management or vacancy. Larger commercial loans often use net operating income instead, but most residential DSCR programs use gross rent. Your actual cash flow will be lower than the ratio suggests.

Which inputs lenders use

Rent

Lenders want a figure they can verify:

• Occupied property: usually the lease, compared with the appraiser's market rent estimate. Many lenders use the lower of the two. Some will accept a higher lease with proof it is being collected.
• Vacant property: the appraiser's market rent estimate.
• Short-term rental: booking history or third-party projections, with rules that vary widely.

Payment

The proposed new loan payment, plus actual or estimated taxes, insurance and dues. On an interest-only loan, some lenders use the interest-only payment and others use a fully amortizing one.

Why two lenders can get different answers

Lenders differ on vacancy factors, whether they stress test the rate, how they handle above-market leases and interest-only payments, and what minimum ratio they require. RSC Private Lending's DSCR Rental program, for example, has a minimum DSCR of 0.75x. The same property can produce a slightly different DSCR, and a different loan amount, from one lender to the next.

Ways to improve the ratio

• Put more money down to shrink the payment
• Shop insurance
• Consider an interest-only option, if your lender offers one and it fits your plan
• Support market rent with strong comparable rentals

What this means for you

Run the formula yourself before you make an offer, using conservative rent and the full payment. If the ratio only works with optimistic numbers, the deal probably needs a lower price or a larger down payment.

Want a lender's read on a property you are considering? Send RSC Private Lending your scenario for a term sheet in 24 hours. All loans are business-purpose and subject to underwriting.