Methodology & data sources
Last updated: 2026-09-24
Calculate Ability is designed around one idea: the answer is less important than knowing how it was reached. Every calculator publishes its formula, and every cost-based default rate carries a source name, URL and as-of date. This page explains how the construction-cost and remodel estimates are built.
Where the cost data comes from
We do not invent numbers. The construction-cost estimator starts from published Canadian and US construction-cost benchmarks, and the remodel estimator starts from published renovation-cost line items. Each default rate is tagged with its source so you can verify it directly.
- Statistics Canada — Residential Renovation Price Index
As of 2025-08-08. Quarterly provincial price movements for residential renovation work.
- RenovateIndex.ca — Canadian Home Renovation Costs
As of 2026-01-01. StatsCan-adjusted costs for ~55 Canadian cities and ~50 renovation services.
- Canada Construction Network — 2026 Provincial Analysis
As of 2026-01-01. Aggregated construction and renovation cost ranges across four Canadian provinces.
- Altus Group — 2026 Canadian Cost Guide
As of 2026-03-27. Annual assessment of Canadian real-estate development and infrastructure hard costs.
- RSMeans / industry averages — US construction costs
As of 2025-01-01. US national-average construction cost data used as a baseline for American projects.
Construction cost estimator formula
The estimator uses a three-step model:
- Base rate: a published cost per square foot for the project type and country, at standard grade.
- Grade factor: scales the base rate up or down for economy, standard, premium or luxury finishes.
- Regional factor: adjusts for local labour and material conditions.
cost/sq ft = base rate × grade factor × regional factor
base cost = square footage × cost/sq ft
total = base cost × (1 + contingency ÷ 100)
Default base rates
| Project type | Canada (CAD/sq ft) | United States (USD/sq ft) |
|---|---|---|
| new home | 245 | 165 |
| addition | 320 | 220 |
| garage | 140 | 95 |
| commercial | 275 | 190 |
| adu | 360 | 250 |
Grade factors
- economy0.78×
- standard1×
- premium1.35×
- luxury1.85×
Regional factors
United States
- Midwest0.92×
- South0.88×
- Northeast1.18×
- West / Pacific1.22×
Canada
- Prairies (AB, SK, MB)0.94×
- Atlantic Canada0.88×
- Ontario1.14×
- Quebec0.98×
- British Columbia1.2×
- Northern / remote1.45×
Remodel estimator formula
The kitchen and bathroom estimator builds a line-item budget from published trade-category rates per square foot, then applies a labour-index multiplier for your market and a layout factor if plumbing or walls move.
line item = room area × rate for tier × labour index × layout factor
total = sum of line items × 1.04 (permits)
The rates differ by country because they are drawn from independent local sources (RenovateIndex for Canada, RSMeans for the United States), not a simple currency conversion.
What these numbers are not
These are planning-stage ranges. They do not replace an itemized contractor quote, a professional cost estimate, a lender's underwriting, or an engineer's sign-off. Local conditions, site access, foundation type, current material pricing and contractor availability can all move a real bid outside the range shown.
If you have your own quote, use the "My own quote" option in the construction-cost estimator to override the published rate per square foot.