Rex says
Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.
Try a scenario
Click to load — tweak from there.Inputs
Result
Total ductwork replacement cost
$8,470
Duct runs
$6,600
Registers, boots, grilles
$1,320
Mastic sealing + testing
$550
Cost per linear ft
$38.50
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How to use this
- 1Enter total duct run (linear ft).
- 2Enter base rate per linear ft ($).
- 3Enter duct material.
- 4Enter access.
- 5Enter supply + return registers.
- 6Enter cost per register (boot + grille) ($).
- 7Enter drywall / finish repair ($).
- 8Read your total ductwork replacement cost on the right — it updates as you type.
- 9Hit Share to keep the scenario or send it to someone.
About this calculator
Replacing ductwork is priced by linear feet of trunk and branch runs plus a per-register charge for boots, grilles, and balancing. The biggest swing factor is access: an open basement or unfinished attic is straightforward, while running new duct through finished walls and tight crawl spaces can double the labor. Material choice matters too — insulated flex is fastest and cheapest for branch runs, sheet metal costs more but performs better in high-static systems and lasts far longer. This calculator prices duct runs, registers, sealing, and optional drywall repair. 2026 US national averages run roughly $25-$55 per linear foot installed, so a typical 1,800 square foot home replacement often lands between $6,000 and $14,000.
Worked example
Using the values the calculator loads with:
Inputs
- Total duct run: 220 linear ft
- Base rate per linear ft: 30 $
- Duct material: Mixed flex + metal trunk
- Access: Typical mixed access
- Supply + return registers: 12
- Cost per register (boot + grille): 110 $
- Drywall / finish repair: 0 $
Results
- Total ductwork replacement cost: $8,470
- Duct runs: $6,600
- Registers, boots, grilles: $1,320
- Mastic sealing + testing: $550
- Cost per linear ft: $38.50
What each field means
Inputs
- Total duct run (linear ft)
- The total duct run used in the calculation, measured in linear ft. Starts at 220 linear ft so you have a working example on load. Accepted range: 20–2000 linear ft.
- Base rate per linear ft ($)
- The base rate per linear ft used in the calculation, measured in $. Starts at 30 $ so you have a working example on load. Accepted range: 10–90 $.
- Duct material
- Pick the option that matches your situation — the maths changes per option. Choices: Insulated flex, Mixed flex + metal trunk, All sheet metal.
- Access
- Pick the option that matches your situation — the maths changes per option. Choices: Open basement / unfinished attic, Typical mixed access, Crawl space or finished walls.
- Supply + return registers
- The supply + return registers used in the calculation. Starts at 12 so you have a working example on load. Accepted range: 1–60.
- Cost per register (boot + grille) ($)
- The cost per register (boot + grille) used in the calculation, measured in $. Starts at 110 $ so you have a working example on load. Accepted range: 30–400 $.
- Drywall / finish repair ($)
- The drywall / finish repair used in the calculation, measured in $. Starts at 0 $ so you have a working example on load. Accepted range: 0–6000 $.
Results
- Total ductwork replacement cost
- Returned as a money amount in US dollars and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Duct runs
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Registers, boots, grilles
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Mastic sealing + testing
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Cost per linear ft
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
Do I need to replace all the ductwork?
Often not. If the trunk lines are sound sheet metal, replacing only failing flex branches, sealing joints with mastic, and adding returns delivers most of the performance gain for a fraction of the cost.
How do I know my ducts are the problem?
Rooms that never reach setpoint, high energy bills with a healthy system, visible disconnected flex in the attic, and a failed duct leakage test all point at distribution rather than equipment.
Should duct replacement happen with a new furnace or AC?
If both are due, yes — the contractor is already in the system, and matching duct sizing to the new equipment's airflow is the only way to get the efficiency you paid for.
Accuracy and limitations
- Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
- Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
- This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Ductwork Replacement Cost Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/ductwork-replacement-cost
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/ductwork-replacement-cost" target="_blank" rel="noopener">Ductwork Replacement Cost Calculator — RevenueLab</a> (2026).</p>
Source: [Ductwork Replacement Cost Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/ductwork-replacement-cost) (2026).