South Dakota Mortgage Calculator (with South Dakota Property Taxes & Insurance)

South Dakota has no state individual income tax, and property tax is one of the primary ways the state and its counties fund schools and local government as a result. That tradeoff shows up directly in this calculator: the 1.02% effective property tax rate applied here is more than double South Carolina's 0.45% and meaningfully higher than Tennessee's 0.45%, reflecting South Dakota's greater reliance on property tax revenue in the absence of income tax collections.

For a household comparing South Dakota against an income-tax state, the higher property tax bill needs to be weighed against the income tax savings. A South Dakota homeowner keeps 100% of their wage income at the state level, which for many buyers more than offsets a property tax bill that runs a few hundred dollars higher per month than in a state like South Carolina, but the net effect depends heavily on income level and home value.

The mortgage math itself, principal and interest on a 30-year fixed loan, is calculated with the same amortization engine used across every mortgage calculator on this platform. Only the property tax rate and accompanying state context differ from state to state.

1. Down payment and loan principal. Down payment percentage is applied to the home price; the remainder becomes the loan principal.
2. Principal and interest (P&I). The loan principal is amortized over 360 months (30 years) at the entered interest rate:

1. Property tax. Home price is multiplied by South Dakota's 1.02% effective rate and divided by 12 for a monthly figure.
2. Insurance. A flat $125 monthly homeowners insurance estimate is added.
3. Total PITI. Principal, interest, tax, and insurance are summed into the headline monthly payment.

Using the calculator's default inputs:

• Home Price: $380,000.00
• Down Payment: 20% ($76,000.00)
• Interest Rate: 6.5%
• Term: 360 months (30 years)

Step by step:

1. Loan principal: $380,000 − $76,000 = $304,000.00
2. Monthly principal and interest at 6.5% over 360 months: $1,921.49
3. South Dakota property tax: $380,000 × 1.02% = $3,876.00 per year, or $323.00 per month
4. Homeowners insurance estimate: $125.00 per month
5. Total monthly PITI: $1,921.49 + $323.00 + $125.00 = $2,369.49
6. Total interest paid over the full 30-year term: $387,732.82

The twelve-row table on this page shows the first year of a 360-row schedule the engine generates in full. Four numbers from that schedule and from sweeping the three inputs describe almost everything a buyer wants to know here.

The crossover, which is real and computed. Payment 1 splits $1,921.49 into $274.82 of principal and $1,646.67 of interest: six dollars of interest for every dollar of equity. The two halves do not cross until payment 232, where the split is $957.19 of principal against $964.30 of interest and interest is still ahead by $7.13. Payment 233 is the first month principal wins, at $962.37 of principal against $959.12 of interest. That is nineteen years and five months into a thirty-year loan. By that month the schedule has already booked $319,812.26 of cumulative interest and the remaining balance is $176,105.09, still more than half the original $304,000 principal.

The cost of the next eighth of a point. Sweeping interestRate in its own 0.125 step, principal and interest runs $1,871.78 at 6.25%, $1,896.56 at 6.375%, $1,921.49 at 6.5%, $1,946.55 at 6.625% and $1,971.74 at 6.75%. Moving from 6.5% to 6.625% costs $25.06 a month, and over the full term it costs $9,021.08 in total interest, $387,732.82 rising to $396,756.31. Half a point, 6.25% to 6.75%, is $99.96 a month and $35,984.97 in lifetime interest on the same $304,000.

The reverse question: what price hits a target payment? Sweeping homePrice at 20% down and 6.5%, total PITI runs $2,133.23 at $340,000, $2,251.36 at $360,000, $2,369.49 at $380,000 and $2,487.62 at $400,000. Each $10,000 of purchase price adds a constant amount to PITI because both moving parts, the 80% financed principal and the 1.02% property tax, scale linearly with price. To hit a target monthly figure, read it off that ladder rather than solving for it.

The 20% down payment line, and why nothing happens there. This is the boundary buyers expect to matter, and in this engine it does not. Sweeping downPaymentPercent across 19.5%, 20% and 20.5%, total PITI runs $2,381.50, $2,369.49, $2,357.48: a smooth $12.01 per half-point of down payment, with no discontinuity at twenty. At 5% down the figure is $2,729.77 on a $361,000 principal. The engine calls generateAmortizationSchedule without a monthlyPMIAmount, so the PMI column of the computed schedule is $0.00 at every down payment from 0% to 100%. Private mortgage insurance is genuinely not modelled, which means every sub-20% figure on this page understates the real payment by whatever a lender would charge.

Right method against wrong method, priced. The common error is applying the quoted rate to the purchase price instead of to the loan principal. Running this calculator at 0% down, so that the financed amount equals the full $380,000, returns $2,401.86 in monthly principal and interest against the correct $1,921.49. That is $480.37 a month overstated, and $484,667.97 of total interest against $387,732.82, an overstatement of $96,933.85 across the term, purely from pricing the rate against the wrong base.

Two limitations sit inside this section rather than beside it. The 1.02% property tax rate is a literal in this calculator's config, not a lookup against the platform's state property tax table. It happens to match the 1.02% the table currently carries for South Dakota, but a correction to that table would not reach this page. And the tax line is computed off the full purchase price, not off the loan balance or any reassessed value: the property tax figure stays at $323.00 a month at 5%, 19.5%, 20% and 20.5% down, and it never falls as the balance amortises.

• Owner-occupied classification discounts. South Dakota offers reduced tax treatment for owner-occupied single-family homes relative to agricultural and commercial property classifications; the 1.02% figure is a statewide approximation, not a county-specific owner-occupied rate.
• County and school district mill levy variation. South Dakota's mill levies are set locally by counties, municipalities, and school districts, and vary meaningfully across the state; 0.56 to 2%+ effective rates are possible depending on location.
• Owner-occupied property tax freeze and relief programs. South Dakota offers property tax relief programs for qualifying elderly and disabled homeowners, which can reduce the effective bill below what this calculator projects for eligible households.
• PMI for down payments under 20%. This calculator does not add private mortgage insurance, which is typically required when the down payment is below 20%.
• HOA dues, well and septic inspection costs, or agricultural exemption nuances. None of these are modeled.
• The offsetting effect of zero state income tax on overall affordability. This calculator only computes the mortgage payment; it does not project take-home pay.

• Assuming South Dakota's overall tax burden is low because there is no income tax. Property tax is comparatively high in South Dakota specifically because it substitutes for income tax revenue; total housing cost should always be evaluated on a PITI basis, not property tax alone.
• Ignoring mill levy differences between counties. A home of identical value in two different South Dakota counties can carry noticeably different tax bills depending on local school and municipal levies.
• Ignoring reassessment cycles. South Dakota counties periodically reassess property values, which can shift your tax bill even when your mortgage rate is fixed.
• Comparing South Dakota's property tax in isolation to income-tax states. A true cost-of-living comparison needs to weigh the property tax difference against income tax savings, not just look at the mortgage payment total.
• Overlooking the down payment threshold for PMI. Below 20% down, expect an additional PMI line item not reflected in this calculator's output.

• South Dakota Department of Revenue: Property tax division and owner-occupied classification guidance. dor.sd.gov
• Consumer Financial Protection Bureau: Regulation Z mortgage disclosure standards and PMI requirements. ecfr.gov/current/title-12/chapter-X/part-1026

Also consulted: South Dakota Department of Revenue: Property tax relief programs for the elderly and disabled.