Cost to Build a Garage Calculator
Enter your garage size, type, and a price per square foot to estimate the cost to build it.
What your result means
Total is the footprint times your price per square foot, which covers a basic shell. Detached garages run $40 to $70 a square foot, attached $35 to $60 since they share a wall and foundation. Add 20 to 30% for finishes (insulation, drywall, an opener, electrical), and budget separately for the slab at $5 to $15 a square foot and the door at $500 to $2,500.
How to use this calculator
- Pick garage size (1-car 12x20, 2-car 22x24, 3-car 30x30).
- Detached or attached.
- Enter cost per sqft based on local quotes.
- Read area and total cost.
- Add 20-30% for finishes (insulation, drywall, doors, electrical).
The formula
Footprint area is length times width. Multiply by your price per square foot for the build cost.
Worked example
Say you're building a 22 by 24 ft detached garage at $50 a square foot. That's 528 sq ft, so a $26,400 base before finishes.
Garage cost reference
| Item | Cost |
|---|---|
| Detached | $40 – $70 / sq ft |
| Attached | $35 – $60 / sq ft |
| Slab foundation | $5 – $15 / sq ft |
| Garage door | $500 – $2,500 |
| Two-car build | $20k – $40k |
Tips & gotchas
- Detached runs $40 to $70 a square foot; attached $35 to $60.
- A single-car garage is $7,000 to $15,000; a two-car $20,000 to $40,000.
- Add $5 to $15 a square foot for the slab foundation.
- Insulation, drywall, and finishes add $5,000 to $15,000.
- A garage door is $500 to $2,500 installed.
Frequently asked questions
How much does it cost to build a garage?
A detached two-car is $20,000 to $40,000; attached is cheaper.
Detached or attached garage?
Attached is cheaper since it shares a wall and foundation; detached gives you more siting freedom.
Do I need a permit for a garage?
Yes, almost always.
How long does it take to build a garage?
4 to 8 weeks from foundation to finish.
Can I DIY a garage?
Skilled DIYers can. Most have a pro do the foundation and frame, then finish it themselves.
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Estimates only — see our full disclaimer.