Construction Cost Estimator

Estimate what a build will cost from square footage, project type, finish quality and your region — with site work, design fees and contingency included, and an honest low-to-high bid range rather than a single number.

Inputs

Floor area

sq ft

Project type

Finish quality

Storeys

Regional cost index

Tab to move between fields

Results

Estimated total cost

$423,403.00

≈ 10 Teslas

Low bid$359,893.00

High bid$529,254.00

All-in cost per sq ft$211.70

Construction rate per sq ft$165.00

Shell construction$330,000.00

Site work$26,400.00

Design & permits$28,512.00

Contingency$38,491.00

Rate basisNew single-family home, Standard

How to Use This Calculator

Enter the finished floor area and pick the project type.
Choose the finish quality — this moves the number more than anything except size.
Adjust the regional index for your market; the base rates are national averages.
Treat the result as a planning range, not a quote. If a builder has given you a local per-square-foot rate, enter it to override the estimate.

How the result changes with Floor area

Floor area	Estimated total cost
20,000	$4,234,032.00
70,000	$14,819,112.00
130,000	$27,521,208.00
180,000	$38,106,288.00

What each input means

Floor area: Finished area of the project.
Project type: Additions cost more per square foot than new build — you are working around an existing structure.
Finish quality: The single biggest lever after size. Luxury finishes roughly double an economy build.
Storeys: Stacking floors on one footprint lowers cost per square foot.
Regional cost index: 100% is the national average. Major metros run 115–160%; rural areas 80–95%.
Local rate per sq ft (optional): If a local builder has given you a per-square-foot figure, enter it here and it replaces the estimate above.
Design & permit fees: Architect, engineering and permits, as a share of construction cost.
Contingency: Reserve for changes and surprises. 10% is a minimum on new build, 15–20% on renovation.

What each result means

Low bid: A competitive bid could land here.
High bid: Overruns are more common than underruns — plan against this end.
All-in cost per sq ft: Total including fees and contingency, divided by floor area.
Construction rate per sq ft: Before site work, fees and contingency.
Site work: Excavation, utilities, grading, drives.

How this is calculated

Formula

total = (rate × sq ft × (1 + site work) × (1 + design fees)) × (1 + contingency)

Worked example, using the default values

Establish the rate per square foot
base × quality × storeys × region
$165 × 1 × 1 × 100% = $165/sq ft
Multiply by the floor area
shell = rate × square feet
$165 × 2,000 sq ft = $330,000
Add site work
site work = shell × 8%
$330,000 × 8% = $26,400
Add design fees and contingency
total = (construction + design) × (1 + contingency)
($356,400 + $28,512) × 1.1 = $423,403
Express as a bid range
low = total × 0.85, high = total × 1.25
$423,403 ± bid spread = $359,893 – $529,254