Ductwork Replacement Cost Calculator

How the four cost lines are built

Replacement is not the same calculation as new installation, even though both start from the same duct-length basis. This calculator adds a removal line the installation calculator does not have — $2–$5 per linear foot for pulling and disposing of the old duct — on top of new material and labor. At the 2,000 sq ft default that alone is 200 × $2 to 200 × $5 = $400–$1,000, before a single foot of new duct is priced.

The duct-length basis itself is identical to the installation calculator and comes from the same two sources: RemodelingCalculator.org states "most homes need about 1 linear foot of ducts, for every 10 square feet of lining (conditioned) space" (0.10 linear ft/sq ft), and Fixr.com bases its figures on a 2,500 sq ft home needing 275 linear feet (0.11). The 0.10 figure this calculator uses gives 200 linear feet for a 2,000 sq ft single-story home, with the same 1.35× multi-story uplift as the installation calculator — that uplift is this calculator's own planning adjustment, not an externally sourced figure, and a real layout comes from an ACCA Manual D design rather than floor area alone.

How material choice moves the total

Sheet metal, flexible duct, and fiberglass carry different per-foot material rates in this calculator — $8–$14, $3–$6, and $5–$10 respectively — but the removal and labor lines apply on top of whichever material is chosen, at the same rates regardless of what is coming out. Switching from sheet metal to flexible duct at the 2,000 sq ft default drops the total to roughly $2,500–$5,200: material falls to $600–$1,200, while removal and labor are unchanged. Accessibility scales labor further — easy access multiplies the labor rate by 1.0, moderate by 1.25, and difficult by 1.6 — so a crawl space job with poor clearance can cost noticeably more in labor alone than the same duct run in an open basement.

The asbestos line, and why it's kept separate

Homes built before roughly 1980 sometimes have asbestos-containing insulation wrapped around ductwork or asbestos tape at the joints. When this calculator's asbestos-risk field is set to "possible," it adds $500–$1,500; set to "confirmed," it adds $1,500–$4,000. That line is deliberately excluded from this page's headline price: it is a conditional hazard-abatement job, not duct replacement itself, and it does not apply to the large majority of jobs. Where remediation is confirmed, abatement must be done by licensed professionals before or alongside the duct work — this calculator's remediation band is a planning add-on, not a substitute for a licensed asbestos inspection.

What this estimate excludes

This calculator prices removal, new material, and labor for the duct run itself. It does not include a Manual D duct redesign, sealing and testing to a specific leakage target, or any drywall and insulation repair needed to access ducts run through finished walls or ceilings. If your home also needs attic ventilation work while the ducts are open, IRC R806 governs the attic ventilation ratio, and that is a separate scope from the duct replacement priced here.

The trade behind the labor rate

Duct replacement is HVAC trade work, and the Bureau of Labor Statistics counted 409,670 HVAC mechanics and installers nationally as of May 2025, with a mean hourly wage of $31.14 and a mean annual wage of $64,780. That sits just below the $65,360 mean annual wage across all construction and extraction occupations — useful context for judging whether a quote's labor line is in line with the trade broadly or running above it for a difficult-access job.

How to read a contractor quote against this estimate

Ask for the same four lines this calculator produces: removal, material by type, labor, and — if the home predates 1980 or has never been tested — a line item for asbestos inspection or remediation. A quote that bundles removal into the material line makes it harder to compare against this page's per-foot basis. And if a contractor's asbestos remediation figure appears without a confirmed lab result, ask what the inspection found; this calculator's $500–$4,000 remediation range is a planning band, not a substitute for testing.