Garage Cost Calculator 2026: What It Really Costs to Build a Garage
Building a garage is one of the highest-value additions to a home — it adds secured parking, storage, workshop space, and resale value. But quotes vary wildly: the same 24x24 detached garage can cost $45,000 from one builder and $120,000 from another. Use our free garage cost calculator to get an instant range for your size, region, and finish level before you talk to contractors.
Get Your Garage Cost Estimate
Enter your garage size, attachment type, and finish level to see an instant 2026 cost range.
Open Free Garage Calculator →Cost to Build a Garage by Size (2026)
| Garage Size | Sq Ft | National Average | California Range |
|---|---|---|---|
| 1-car | 240–288 | $18,000–$40,000 | $30,000–$70,000 |
| 2-car | 480–576 | $35,000–$75,000 | $60,000–$130,000 |
| 3-car | 660–864 | $48,000–$105,000 | $85,000–$170,000 |
| RV garage | 600–800+ | $45,000–$110,000 | $80,000–$180,000 |
Per-square-foot costs run $70–$130 nationally and $110–$220 in coastal California. The shell (foundation, framing, roof, siding) is only part of the total — finishes and site work move the number more than most owners expect.
What Drives the Cost Up or Down
- Attached vs detached: Attached garages run 10–20% cheaper per square foot (shared wall, shared roof tie-in). Detached avoids firewall complications and can later become an ADU.
- Driveway work: A new driveway adds $15,000–$30,000 if the garage site doesn't already have one.
- Finish level: Bare studs + door is the floor. Insulation, drywall, epoxy floors, and finished electrical can add $20–$50/sq ft.
- Garage doors: A single 8x7 door runs $1,500–$3,500 installed; a 16x7 double door $2,500–$6,000. Insulated doors cost 30–50% more.
- Permits: $4,000–$10,000+ in most California cities, with 6–12 weeks of plan check.
Attached vs Detached: Which Should You Build?
| Factor | Attached | Detached |
|---|---|---|
| Cost per sq ft | 10–20% cheaper | Higher |
| Firewall requirements | Stricter code | Simpler |
| Future ADU conversion | Harder | Easier — design for it now |
| Design flexibility | Constrained by house | Free placement on lot |
If you might convert the garage to an ADU later, build it conversion-ready: 9-foot ceilings, an extra electrical panel slot, water and sewer stubs to one wall, and a mini-split or HVAC ductwork. Adding these during construction costs $8,000–$20,000; retrofitting them later costs far more.
Prefab vs Stick-Built Garage
Prefab steel garages run $15–$40/sq ft for the structure — dramatically less than stick-built. But they typically don't include foundation, insulation, drywall, or electrical, and many HOAs and city design review boards reject them in residential zones. In California, a finished stick-built garage is usually the only option that appraises and permits cleanly.
Garage Remodel Cost
Converting or upgrading an existing garage is a different budget: a basic garage refresh (flooring, paint, storage, door upgrade) runs $5,000–$15,000. A full living-space conversion runs $80,000–$150,000+ in California and triggers different code requirements (ceiling height, egress, insulation, fire separation). See our garage conversion calculator for that path.
How to Get an Accurate Number Before You Call a Builder
Builders quote what you describe, and vague descriptions get padded. Before collecting bids, know your target size, attachment type, door count, finish level, and whether the site needs grading or a new driveway. Run those inputs through the garage cost calculator, walk in with a range, and bids that fall far outside it need a written explanation.