How to Use This Calculator
- Enter outside garage width and length.
- Choose parking capacity, attachment type, and finish level.
- Replace the example rate and adjustment with your own assumptions, then calculate.
Calculation Formula
Worked Example
A 24 ft × 24 ft garage contains 576 sq ft. At $75 per sq ft, base cost is $43,200. A standard 12% finish adjustment adds $5,184. If detached adds another 8%, total reaches $51,840.
Factors That Affect the Estimate
- Slab, frost wall, basement, or other foundation
- Roof shape, span, storage, and structural loads
- Doors, windows, siding, and roofing selections
- Electrical, plumbing, heating, and insulation
- Driveway, grading, drainage, permits, and utilities
Frequently Asked Questions
Does parking-space count change the cost?
The calculation uses actual width and length. Space count is shown for planning context and does not override area.
What does detached adjustment cover?
It is a customizable planning allowance for duplicated exterior work and utility connections, not a guaranteed premium.
Does this include a driveway?
No. Add driveway and site work separately.
Can I estimate a workshop?
Yes, if you adjust dimensions, base rate, and finish assumptions to cover the workshop scope.
Are garage costs the same nationwide?
No. Labor, materials, codes, foundations, and site conditions vary substantially.
Important Disclaimer
This calculator provides a planning estimate only. It is not a bid, appraisal, or professional construction advice. Confirm quantities, code requirements, labor, permits, taxes, site conditions, and current local prices with qualified professionals before making financial decisions.