Missouri pricing

Air Duct Replacement Cost Calculator — Missouri

Estimate duct replacement cost from your home's size, run count and how hard the attic or crawlspace is to work in. Every figure below is already adjusted for Missouri labor and material pricing.

Verified August 2026

Does ductwork replacement cost cost more in Missouri?

-10% versus the national baseline

Permitting varies more within Missouri than between many states — St. Louis County municipalities can require full review while nearby unincorporated areas require little. Permit fees here run about -15% off the national average, and Homeowner permits widely allowed

Estimated total cost

$6,386 – $9,069

Cost per square foot
$4
Cost per supply run
$725

Estimates only. Local pricing, site conditions and code requirements change the real number.

What changes the number in Missouri

Local cost indexBelow the national baseline0.90x national
Permit fee index0.85x national
Code basisAdopted locallyLocal adoption of the IRC; no statewide residential code
Owner-builder postureHomeowner permits widely allowed
Largest marketsKansas City, St. Louis, Springfield, Columbia

The formula

Cost = (sq ft x rate) + (runs x per-run cost) x access multiplier + permit

Duct replacement is priced mostly by labor hours. Tight crawlspaces and low attics can add 30–50% over an open, walkable space.

Frequently asked questions

How much does it cost to replace ductwork?

Whole-home duct replacement usually runs $3,500 to $12,000 in 2026, or roughly $2 to $4 per conditioned square foot.

Should I replace ducts with the HVAC system?

If ducts are over 20 years old, undersized or badly leaking, doing both at once saves labor and protects the new system's efficiency rating.

Sources

Sources & verification

Last verified August 2026. Cost figures are modeled estimates based on national baselines adjusted for local labor and material pricing — they are not quotes. Permit rules change; confirm with the building department before starting work.