Local Mortgage Calculator
Plan with a $399,600 city home-value benchmark, a 1.78% property-tax estimate drawn from city-level data for Johnston, IA, and transparent down-payment and cash-to-close scenarios for Johnston.
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Local payment snapshot
This mortgage payment calculator in Johnston, Iowa uses a typical home-value benchmark of $399,600, 20% down, a 6.75% 30-year fixed planning rate, a 1.78% effective property-tax estimate based on city-level data for Johnston, IA, and a 0.35% annual homeowners-insurance assumption.
City home value
$399,600
Down payment
$79,920
Principal & interest
$2,073/mo
Property tax
$593/mo
Estimated payment
$2,783/mo
Includes $117/mo for homeowners insurance. PMI is $0 with the 20% down assumption.
Home value: August 2026 | Zillow Home Value Index (ZHVI)
The Johnston home-value benchmark is $160,100 (66.8%) above the $239,500 Iowa benchmark. At 20% down, the local benchmark translates to $79,920 upfront and a $319,680 starting loan balance before closing costs. This comparison helps separate the local price level from the statewide number instead of treating every Iowa market as interchangeable.
Applying the 1.78% effective rate from city-level data for Johnston, IA to the page's home-value benchmark produces about $7,116 per year, or $593 per month. The rate is 0.11 percentage points above the 1.67% median among the nearby cities on this page. The estimate is useful for budgeting, but a parcel's actual bill can change with assessed value, exemptions, and overlapping taxing districts.
Closing costs are separate from the down payment. Using a planning range of 2% to 6% of the $399,600 benchmark adds approximately $7,992 to $23,976 before moving expenses and cash reserves. Combined with 5% down, that suggests roughly $27,972 to $43,956 in initial cash. At 20% down, the comparable range is $87,912 to $103,896. A lender's loan estimate and the selected property's prepaid taxes, insurance, and HOA charges will determine the actual amount.
These examples hold the $399,600 home-value benchmark, 6.75% planning rate, 30-year term, tax estimate, and insurance assumption constant. That isolates what changes when the down payment changes.
| Down payment | Cash down | Loan amount | Estimated PMI | Estimated payment |
|---|---|---|---|---|
| 5% | $19,980 | $379,620 | $333/mo | $3,504/mo |
| 10% | $39,960 | $359,640 | $333/mo | $3,375/mo |
| 20% | $79,920 | $319,680 | $0/mo | $2,783/mo |
Nearby city comparison
Nearby cities are selected by approximate straight-line distance using U.S. Census Bureau representative coordinates. Each comparison uses that location's own published home-value benchmark, 20% down, the same 6.75% planning rate, and its available city, county, or state property-tax estimate.
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A down payment is only one part of the money due at closing. The examples below combine each down-payment choice with a 2% to 6% closing-cost planning range at the $399,600 benchmark. They do not include moving expenses or the emergency reserves you may want to keep after closing.
| Down payment | Cash down | Closing-cost range | Estimated cash to close |
|---|---|---|---|
| 5% | $19,980 | $7,992-$23,976 | $27,972-$43,956 |
| 10% | $39,960 | $7,992-$23,976 | $47,952-$63,936 |
| 20% | $79,920 | $7,992-$23,976 | $87,912-$103,896 |
Closing costs can include lender charges, title and settlement services, appraisal fees, prepaid taxes and insurance, and initial escrow deposits. Seller or lender credits may reduce the amount paid at closing.
The home-value benchmark comes from the Zillow Home Value Index for August 2026 and is labeled as a city-level figure. The 1.78% effective property-tax estimate uses city-level data for Johnston, IA from 2024 owner-occupied housing data and is converted to monthly dollars against the same home-value benchmark. Nearby comparisons use representative coordinates and the same payment formula so the direction of the differences is easier to interpret.
Insurance is modeled at 0.35% of home value annually, conventional PMI at 1% annually below 20% down, and principal and interest at a 6.75% 30-year fixed planning rate. These are transparent comparison assumptions, not live quotes. Actual price, parcel taxes, insurance, HOA dues, closing costs, rate, APR, lender fees, and prepaid amounts can differ. This page does not provide financial, legal, lending, or real-estate advice.
Using a $399,600 home-value benchmark, 20% down, a 6.75% 30-year fixed planning rate, a 1.78% property-tax estimate, and a 0.35% annual homeowners-insurance assumption, the estimated monthly housing payment is $2,783. Change the calculator inputs for a personalized scenario.
It uses the $399,600 Zillow Home Value Index benchmark published for Johnston for August 2026. The Iowa statewide benchmark for the same source is $239,500.
The page applies a 1.78% effective property-tax estimate from city-level data for Johnston, IA. At the $399,600 benchmark, that contributes about $593 per month or $7,116 per year. A parcel's actual bill can differ because of assessed value, exemptions, and taxing districts.
At the current benchmark, 5% down is $19,980 with an estimated $3,504 monthly payment. At 20% down, cash down is $79,920 and the estimated payment is $2,783, with no conventional PMI included in that example.
At the $399,600 benchmark, a 5% down payment plus a 2% to 6% closing-cost planning range equals approximately $27,972 to $43,956. With 20% down, the comparable range is $87,912 to $103,896. Actual lender charges, prepaid taxes, insurance, escrow deposits, and credits will change the final amount.
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