Garage Conversion Cost Calculator

ADU conversion cost from garage dimensions and scope.

Garage sq ft

Garage doors to replace

Conversion type (0-2)

Add bathroom (0/1)

Add kitchen (0/1)

Floor leveling needed (0/1)

Contingency %

Tab to move between fields

Total conversion cost ($)

$54,177.00

≈ 5 years of state college

Cost per sq ft ($)$135.00

Materials subtotal ($)$35,180.00

Labor cost ($)$14,072.00

Floor work ($)$8,000.00

Door replacement ($)$9,000.00

Walls & ceiling ($)$4,880.00

Electrical ($)$4,000.00

HVAC ($)$2,500.00

Contingency ($)$4,925.00

Est. monthly rent ($)$0.00

Payback period (months)0

How to Use This Calculator

Enter the garage square footage and the number of garage doors to be replaced or infilled.
Select conversion type (living space, ADU/in-law suite, or home office).
Toggle bathroom and kitchen additions if the conversion will include them.
Review total cost, cost per square foot, and the breakdown of structural, insulation, and finish work.
Check estimated permit costs and confirm zoning allows the planned conversion in your area.

How the result changes with Garage sq ft

Garage sq ft: Total square footage of the garage to convert.
Garage doors to replace: Number of garage door openings to fill with wall/windows.
Conversion type (0-2): 0 = Basic room, 1 = Studio/office, 2 = Full ADU (kitchen + bath).
Add bathroom (0/1): 1 = Add a bathroom (auto-included for ADU type).
Add kitchen (0/1): 1 = Add a kitchenette (auto-included for ADU type).
Floor leveling needed (0/1): 1 = Garage floor needs leveling to match house (~$12/SF), 0 = Floor is level.
Contingency %: Buffer for unexpected issues (10% recommended).

Total conversion cost ($): All-in cost including labor and contingency.
Cost per sq ft ($): Total cost divided by garage area.
Materials subtotal ($): All materials before labor.
Labor cost ($): Estimated labor cost.
Floor work ($): Leveling, subfloor, insulation, and finish floor.
Door replacement ($): Replacing garage doors with insulated walls and windows.
Walls & ceiling ($): Insulation and drywall for walls and ceiling.
Electrical ($): Full electrical build-out.
HVAC ($): Heating and cooling installation.
Contingency ($): Buffer for unexpected costs.
Est. monthly rent ($): Estimated rental income if used as ADU (ADU type only).
Payback period (months): Months to recoup investment from rental income.

Identify Input Parameters
4 parameters
Garage sq ft = 400, Garage doors to replace = 2, Conversion type (0-2) = 1, Add bathroom (0/1) = 0 = 7 input(s) provided
Calculate Total conversion cost
Total conversion cost = subtotal + contingency
54177 = $54,177
Calculate Cost per sq ft
135 = $135
Calculate Materials subtotal
Materials subtotal = floorCost + flooringFinish + doorReplacementCost + wallInsulationDrywall +
35180 = $35,180