Ductwork Replacement Cost Calculator: DIY vs Hiring a Pro
A few runs, a whole house in flex, or sheet metal: DIY from $327, an HVAC contractor from $450.
- Pick the job closest to yours. The whole-house sizes assume a 1,500 sq ft single-story with about 200 ft of duct and 10 registers; scale by register count for a bigger house.
- On the DIY tab, materials are the whole cost — flex duct, collars, mastic, straps, boots — so untick tools you own and put a real number on the hours. Attic work takes twice as long as you'd guess.
- On the Hire a pro tab, tick new plenums, a leakage test and the permit for any whole-house job, and Manual D design if rooms have never been comfortable — those are the lines a bare quote omits.
- The flex jobs show DIY saving 70% or more; the sheet metal system saves 35% on paper but needs fabrication skills the calculator can't price.
Calculate cost
| Tools to buy or rent | $97 |
|---|---|
| Materials | $1,023 |
| Disposal | $99 |
| DIY cash cost | $1,219 |
| Your time (19 h × $25) | $475 |
| DIY all-in | $1,694 |
DIY saves about $2,806 after valuing your time ($3,281 in cash).
National estimates for planning. Doesn't include the risk-side costs described on the comparison page.
Typical results by job size
Defaults the calculator starts from: commonly owned tools excluded, typical pro price, no add-ons.
| Size | Verdict | DIY | Pro | Your hours | Typical savings | Break-even |
|---|---|---|---|---|---|---|
| A few damaged runs | DIY | $327–$587 | $450–$1,200 | 3–5 hours | $293 (39%) | $73/hour |
| Whole house, flex ducts in the attic | DIY | $1,120–$1,518 | $3,000–$7,000 | 14–24 hours | $3,181 (71%) | $167/hour |
| Whole house, ducts in a crawl space | DIY | $1,182–$1,592 | $3,500–$8,000 | 18–30 hours | $4,113 (75%) | $171/hour |
| Two-story, sheet metal trunk and branches | Hire | $6,202–$6,762 | $7,000–$15,000 | 40–70 hours | $3,518 (35%) | $64/hour |
Break-even is what an hour of your time would have to be worth for DIY and hiring to cost the same. Above it, hiring is cheaper all-in. See how these are calculated.
Reading the result
The job you pick applies to both tabs.
Do it yourself totals R-8 flex duct (or sheet metal trunk and pipe on the two-story option), take-off collars, mastic and tape, straps and hanger strap, and boots and grilles for the whole-house sizes, scaled to the job — plus the strap tensioner, snips and safety gear you don’t own, disposal of the old ducts, a permit where one applies, and your time at the rate you set. Hours are 3–5 for a few runs, 14–24 for an attic house, 18–30 on a crawl space, 40–70 for a sheet metal system.
Hire a pro starts from a low, typical or high installed price for that scope, then adds what a base quote often leaves out: new supply and return plenums, an added return, mastic sealing with a leakage test, a Manual D design for resized runs, an upgrade from flex to metal, drywall repair for ducts in finished spaces, asbestos testing on pre-1980 material, zoning, and the permit. Tick what applies and compare.
What neither tab includes: a system that was undersized to begin with. Copying the old layout — which is what both the DIY figure and a basic quote do — copies its problems. If rooms have never heated or cooled properly, the Manual D add-on is the honest price of fixing that, and the full comparison explains why it isn’t a DIY line. The DIY guide covers the job where it is.
Frequently asked questions
How do I count my ductwork for the calculator?
Count the supply registers in the house — each is one run — and the return grilles. Then estimate linear feet: from the air handler to the farthest register along the path the duct actually takes, for each run, or use 15–25 ft per run as a rule of thumb for a single-story. A 1,500 sq ft house is usually 8–12 supply runs and 150–250 ft; a 2,500 sq ft two-story 14–18 runs and 300–350 ft. Match the closest size and scale the materials by your run count.
Why is the DIY figure for the sheet metal system so much higher than for flex?
Because sheet metal costs $12–$18 per foot in materials against $2–$3 for flex, and a fabricated trunk with fittings, dampers and insulation wrap is $5,000 and up on its own for a two-story house. The pro price is higher too, so the saving is still about $3,500 — but crimping, seaming and hanging metal trunk is a trade, and the calculator prices the material, not the skill. Most homeowners who tackle ductwork stick to flex.
What do the quote levels mean for ductwork?
Low is an easy attic, flex reused on sound plenums, an inexpensive market or a contractor who's already on site for equipment. Typical is the national median for that scope with removal, R-8 flex, mastic sealing and boots. High is a difficult attic or crawl space, a coastal metro, or an above-code spec. Plenums, returns, design work, testing, drywall and the permit are add-ons on any level.
Sources
- Heating, Air Conditioning, and Refrigeration Mechanics and Installers (SOC 49-9021), Occupational Employment and Wage Statistics , U.S. Bureau of Labor Statistics, 2026-04
- How Much Does It Cost to Install or Replace Ductwork? , HomeGuide, 2026-09
- How Much Does Duct Replacement Cost? , Angi, 2026-09
- How Much Does It Cost to Install Ductwork? , HomeAdvisor, 2026-09
- Duct Sealing , ENERGY STAR, U.S. Environmental Protection Agency, 2026-09
- Minimizing Energy Losses in Ducts , U.S. Department of Energy, 2026-09
- International Residential Code, Chapter 16: Duct Systems , International Code Council, 2026-09
- Manual D: Residential Duct Systems , Air Conditioning Contractors of America, 2026-09
Figures last reviewed . See how we estimate.