When you apply for a conventional mortgage in South Dakota, lenders use two key ratios to decide how much you can borrow: the front‑end ratio (housing costs) and the back‑end ratio (all debt).

Front‑end ratio – 28 % rule

The front‑end ratio limits your monthly housing payment (principal, interest, property taxes, and homeowner’s insurance) to roughly 28 % of your gross monthly income. Lenders set this ceiling to ensure you have enough cash flow left for other living expenses.

Back‑end ratio – 36 % rule

The back‑end ratio adds any other recurring debts—car loans, student loans, credit‑card payments—to the housing cost. The total should not exceed about 36 % of your gross monthly income. This broader test protects both you and the lender from over‑extension.

Down payment and private mortgage insurance (PMI)

Conventional loans typically accept a down payment as low as 3 % of the home’s price. If you put down less than 20 %, lenders usually require PMI, which protects the lender in case of default. Reaching a 20 % down payment eliminates PMI, reducing your monthly payment.

Loan limits and South Dakota specifics

  • Conventional mortgages are capped at the federal conforming loan limit, which is updated annually and varies by region. Most of South Dakota falls under the standard limit.
  • South Dakota has no state income tax, which can improve your debt‑to‑income calculations because taxable income isn’t reduced by state tax withholdings.
  • Many closings in the state are handled by attorneys rather than title companies, which can affect closing‑cost estimates.

First‑time‑buyer programs and other state‑specific assistance may help you meet the down‑payment requirement, but eligibility rules differ.

This article provides general information and should not be taken as personalized financial advice.