DSCR and Loan Sizing Calculator
Enter a year's cash flow available for debt service and the terms of a loan, and the calculator returns the payment, the debt service coverage ratio, and the largest loan the cash flow supports at the coverage you set, beside a loan-to-cost limit.
The calculator
This calculator runs in your browser. Nothing you type is sent anywhere or kept: no network request, no cookie, no storage. Results update as you type.
Your inputs
Results
- Monthly payment
- Annual debt service
- Loan constant (annual debt service per dollar of loan)
- Debt service coverage on the loan requested
- Cash flow needed at the target coverage on this loan
- Largest loan the cash flow supports at the target coverage
- Loan at the loan-to-cost limit
- Largest loan under both tests
- The test that binds
- Largest loan less the loan requested (a negative figure is a shortfall)
A field left empty counts as not entered, and the results that need it read "not computed"; fields that say "Leave empty for none" count as zero.
What it computes, and the formulas
Debt service coverage divides a year's cash flow available for debt service by a year's payments on the loan. A lender reads the ratio against a floor; run backwards, the same arithmetic gives the largest loan the cash flow carries at that floor. This calculator does both, and beside the coverage test it applies a loan-to-cost limit, so it shows which of the two sets the loan.
- Monthly rate: r = annual interest rate ÷ 12. Number of payments: n = amortization in years × 12.
- Monthly payment on a loan L: P = L × r ÷ (1 − (1 + r)−n); at a zero rate, P = L ÷ n.
- Annual debt service: D = 12 × P. Loan constant: D ÷ L.
- Debt service coverage: DSCR = C ÷ D, where C is the cash flow available for debt service.
- Cash flow needed at a target coverage T: D × T.
- Largest loan at the target coverage: LT = (C ÷ T ÷ 12) × (1 − (1 + r)−n) ÷ r, the payment formula run backwards.
- Loan at the loan-to-cost limit: LC = total project cost × maximum loan-to-cost.
- Largest loan under both tests: the smaller of LT and LC; the smaller one is the test that binds. The last line is that loan less the loan requested.
Enter C as the methodology article defines it: after operating costs, the owner's pay at a market wage and a replacement reserve, before interest, depreciation and income tax. Enter T as the floor that binds on the loan, which is the higher of the program's floor and the lender's own policy.
What it does not do
- An estimate, not a feasibility study: it takes the cash flow you enter as given and tests nothing behind it against a market.
- Not an appraisal: it states no value for a property, and a loan-to-cost limit is not a loan-to-value test.
- Not lending advice: a lender sizes a loan on its own credit policy, its program's rules and its own reading of the cash flow.
- One year and one loan: a fully amortizing loan in equal monthly payments at a fixed rate, with no interest-only period, balloon, fees or second lien. An SBA 504 project carries a bank's first lien and the CDC's debenture, and its coverage is tested on both payments together, which this calculator does not combine.
- The answer is only as good as the cash flow line. A start-up covers less in its first years than in its stabilized year, and the year a floor is tested on matters as much as the floor.
The method behind these tests is set out in the methodology series: Debt Service Coverage in a Feasibility Study: How the Ratio Is Built, and Which Floor Binds.
Worked example
The cash flow, loan, rate, term and target coverage are the illustration in the methodology article on debt service coverage, where 1.25x is a stated lender assumption, not a program rule; the project cost and the loan-to-cost limit are added here to show the second test. None of these inputs is data or a forecast for any project.
| Cash flow available for debt service, per year | $455,000 |
|---|---|
| Loan requested | $3,400,000 |
| Interest rate, per year | 9.25% |
| Amortization | 25 years |
| Target coverage | 1.25x |
| Total project cost (optional) | $4,500,000 |
| Maximum loan-to-cost (optional) | 80% |
| Monthly payment | $29,117 |
|---|---|
| Annual debt service | $349,404 |
| Loan constant (annual debt service per dollar of loan) | 10.28% |
| Debt service coverage on the loan requested | 1.30x |
| Cash flow needed at the target coverage on this loan | $436,755 |
| Largest loan the cash flow supports at the target coverage | $3,542,034 |
| Loan at the loan-to-cost limit | $3,600,000 |
| Largest loan under both tests | $3,542,034 |
| The test that binds | the coverage test |
| Largest loan less the loan requested (a negative figure is a shortfall) | $142,034 |
SBA median loan and charge-off floors, by class with a payback calculator
| Class and program | Loans approved | Median loan | Charged off (floor) | Charged off within five years (floor) |
|---|---|---|---|---|
| Gas station and truck stop, SBA 7(a) | 6,403 | $1.1 million | 1.2% | 0.51% |
| Gas station and truck stop, SBA 504 | 954 | $860,000 | 0.85% | 0.00% |
| Car wash, SBA 7(a) | 2,713 | $789,000 | 2.5% | 1.5% |
| Car wash, SBA 504 | 997 | $1.1 million | 1.00% | 0.75% |
| Hotel and motel, SBA 7(a) | 8,942 | $2.2 million | 0.99% | 0.27% |
| Hotel and motel, SBA 504 | 2,885 | $2.0 million | 0.55% | 0.09% |
| Multifamily (lessors of residential buildings), SBA 7(a) | 204 | $152,500 | 4.3% | 4.3% |
| Multifamily (lessors of residential buildings), SBA 504 | 11 | $461,000 | not reported: fewer than 30 loans in the cohort | not reported: fewer than 30 loans in the cohort |
| Grocery store, SBA 7(a) | 3,701 | $310,000 | 7.6% | 3.8% |
| Grocery store, SBA 504 | 488 | $846,000 | 0.00% | 0.00% |
| Liquor store, SBA 7(a) | 6,438 | $440,000 | 2.5% | 1.2% |
| Liquor store, SBA 504 | 302 | $555,500 | 0.00% | 0.00% |
| Nonresidential lessor (flex, office and retail investor buildings), SBA 7(a) | 1,486 | $597,000 | 0.82% | 0.59% |
| Nonresidential lessor (flex, office and retail investor buildings), SBA 504 | 81 | $602,000 | 0.00% | 0.00% |
| RV park and campground, SBA 7(a) | 645 | $821,000 | 0.00% | 0.00% |
| RV park and campground, SBA 504 | 281 | $576,000 | 0.00% | 0.00% |
| Self storage, SBA 7(a) | 1,584 | $975,000 | 0.50% | 0.12% |
| Self storage, SBA 504 | 946 | $890,000 | 0.00% | 0.00% |
Both charge-off columns are floors: SBA withholds the status of open loans, so a loan counts as charged off only once SBA reports it, and a rate needs at least 30 loans in its cohort and is otherwise not reported. How the floor is built: The Approval-Cohort Charge-Off Floor: Why a Published SBA Loss Rate Can Only Understate.
Gas station and truck stop: The code is the borrower's industry. Truck stop or travel center cannot be split out. EV charging has no entry in the 2022 NAICS index. Shared code: Truck stops and travel centers sit inside 457120 with gas stations that have no convenience store.
Car wash: Car and truck washes, including mobile washes, share one code. Shared code: Truck washes share 811192.
Hotel and motel: One code for hotels and motels; limited service and full service cannot be separated. Shared code: Hotels and motels share 721110.
Multifamily (lessors of residential buildings): SBA loans to residential lessors are rare and nearly stop from FY2024 (measured in the profile); a class with very few loans. Shared code: Build-to-rent has no own code.
Nonresidential lessor (flex, office and retail investor buildings): Flex space cannot be separated from office or retail lessors. Nearly stops from FY2024. Shared code: Flex, office, retail and banquet hall rental share 531120.
RV park and campground: One code for RV parks and campgrounds. Shared code: RV parks, RV resorts and campgrounds share 721211.
Self storage: RV and boat storage cannot be separated from self storage. Shared code: RV and boat storage has no own code; it is self storage (531130) or other warehousing (493190).
For the lessor classes, SBA lending almost stops from FY2024: SBA treats most lessor businesses as passive and ineligible, so the record here is mostly older loans.
Source: U.S. Small Business Administration, 7(a) and 504 loan-level FOIA files (data.sba.gov), as of 2026-09-30; Loan Analytics loan-outcome cells PA-C01-7A, PA-C01-504, PA-C02-7A, PA-C02-504, PA-C07-7A, PA-C07-504, PA-C06-7A, PA-C06-504, PA-C40-7A, PA-C40-504, PA-C37-7A, PA-C37-504, PA-C09-7A, PA-C09-504, PA-C03-7A, PA-C03-504, PA-C04-7A, PA-C04-504.
Each row links to that class's payback calculator; RV storage uses the self storage record, and retail the nearest retail classes. All calculators.
Cite this calculator
Loan Analytics. "DSCR and Loan Sizing Calculator." https://www.analytics.loan/tools/dscr-loan-sizing-calculator. SBA loan data as of 2026-09-30; page built 2026-11-10.
Methodology
- Debt Service Coverage in a Feasibility Study: How the Ratio Is Built, and Which Floor Binds
- The Loan Analytics methodology series
SBA program pages
Other calculators
Start with the data.
Contact Us