Free Ductwork Replacement Cost Calculator Online
Old, leaky, or inefficient ductwork can waste energy, reduce airflow, and leave rooms hot or cold no matter how powerful your HVAC system is. Whether you’re dealing with deteriorating insulation, crushed flex ducts, or noisy airflow, replacing ductwork can make a big difference in comfort and energy bills. The Ductwork Replacement Cost Calculator provides an accurate estimate for replacing residential or light commercial air ducts based on linear footage, materials, insulation type, access difficulty, and labor.
This calculator helps homeowners, HVAC technicians, and remodelers understand what to budget when updating ductwork in attics, basements, or crawlspaces.
What is a Ductwork Replacement Cost Calculator?
A Ductwork Replacement Cost Calculator is a tool that estimates the total expense of removing old air ducts and installing new ones in a home or building. The estimate considers duct length in linear feet, type of ducting (flex, sheet metal, or fiberglass), insulation requirements, labor, demolition, and final air balancing.
Unlike basic square-foot HVAC pricing, this calculator gives a detailed cost based on how many feet of duct are needed, how complex the routing is, and whether the ducts are in attics, walls, or floors. It helps plan for complete system overhauls or partial replacements during HVAC upgrades or renovations.

Why Accurate Duct Cost Estimation Matters
Prevent Budget Surprises
HVAC ductwork isn’t always visible—but it makes up a big chunk of system cost.
Improve Energy Efficiency
New ducts reduce air leakage and increase system performance.
Plan Renovation Projects
If you’re opening walls or replacing ceilings, it’s the perfect time to replace ductwork.
Compare Material Types
Flexible duct, sheet metal, and pre-insulated fiberglass duct each have different price points.
What’s Included in the Estimate?
Linear Duct Runs
Measurement of supply and return lines, usually in feet.
Duct Material Type
Options include flexible duct, galvanized sheet metal, or fiberglass duct board.
Insulation Level
Uninsulated, R-6, or R-8 depending on code or attic location.
Labor Costs
Includes removal, installation, sealing, and support strap placement.
Demolition and Disposal
Removal of old ductwork, debris hauling, and ceiling repair if needed.
Registers and Grilles
New supply and return vents, diffusers, or boots.
Air Balancing
Testing and adjusting for even airflow across all zones.
Permits or Inspections
Required in many states for HVAC system changes.
Price Range Estimates
- Flexible duct (standard): $10 – $20 per linear foot installed
- Sheet metal duct: $20 – $35 per linear foot installed
- Return duct with filter grill: $150 – $400 per unit
- Full duct replacement in 2,000 sq. ft. home: $5,000 – $12,000+
Cost varies with ceiling type, access conditions, duct length, and system complexity.
Key Formulas for Duct Cost Estimation
1. Duct Material Cost $$\text{Material Cost} = \text{Linear Feet} \times \text{Cost per Foot (by duct type)}$$
This determines total duct material cost for supply and return runs.
2. Full Project Estimate $$\text{Total Cost} = \text{Duct Cost} + \text{Labor} + \text{Insulation} + \text{Demo} +$$
Helps approximate how many feet of ductwork are needed in homes without exact plans.
How to Use the Ductwork Replacement Cost Calculator
- Enter the Total Home Size
Typically in square feet, which helps estimate airflow requirements. - Select Duct Type
Choose flex, metal, or fiberglass based on your system or building code. - Enter Total Linear Footage
Based on system size or room-by-room input. - Specify Insulation Level
Add R-6 or R-8 insulation values for unconditioned spaces. - Include Access Conditions
Attic, crawlspace, or inside-wall ducts may have higher labor rates. - View Final Estimate
The calculator outputs a full price range including material, labor, and extras.
Typical Residential Replacement Projects
Attic Flex Duct Replacement
Common in warm climates. Flex duct is easy to install and affordable, especially in open attic spaces.
Sheet Metal Duct Upgrade
Used in older homes or custom systems. Requires more labor but offers high durability and minimal air resistance.
Crawlspace Duct Install
Often paired with insulation wraps and vapor barriers to protect from moisture.
Full Home HVAC Remodel
All ducts replaced during a major renovation or HVAC system change-out.
Real-Life Example
A homeowner with a 2,200 sq. ft. house wants to replace 120 linear feet of attic duct with R-8 insulated flex duct. Their HVAC contractor quotes:
- Flex duct install (120 x $18) = $2,160
- Old duct removal and haul-off = $450
- Registers and grilles = $400
- Final testing and balancing = $300
- Total Estimated Cost = $3,310
The calculator confirms this quote is within the average range and helps justify the investment.
Factors That Affect Cost
- Duct layout complexity
- Ceiling access (vaulted vs drop)
- Insulation code requirements
- Supply vs return duct sizes
- Number of takeoffs and elbows
- Labor rates by region
Who Should Use This Calculator?
- Homeowners replacing old HVAC systems
- Builders estimating new home HVAC cost
- HVAC technicians quoting duct retrofits
- Property managers planning system upgrades
- Energy auditors assessing efficiency projects
Common Mistakes to Avoid
- Only calculating duct length without accounting for fittings
- Forgetting to include return air pathways
- Reusing old grilles or boots without sealing
- Not balancing airflow after replacement
- Skipping permits and inspection where required
Duct System Efficiency Matters
Leaky or undersized ducts can reduce HVAC efficiency by up to 30%. New ductwork improves:
- Indoor air quality
- Heating and cooling distribution
- Energy bills
- System lifespan
The calculator helps homeowners see how duct replacement can reduce long-term costs and increase comfort.
Benefits of Estimating Upfront
- Plan budgets for system upgrades
- Avoid change orders or cost overruns mid-project
- Compare duct types with clarity
- Decide between partial vs full replacement
- Justify energy improvement investments to utility rebate programs
Final Thoughts
The Ductwork Replacement Cost Calculator simplifies what’s often an overlooked but critical part of home comfort. Whether you’re updating an aging HVAC system, building a new home, or fixing airflow issues, this tool gives you the numbers you need to make smart decisions. From duct layout to insulation to labor, the calculator breaks down every phase so you can plan your project with confidence.
Use it before you start demo, and ensure your air moves efficiently and affordably throughout your home.