Roofing methodology

How We Calculate

Last updated: June 2026

Our calculators use shared assumptions: planning inputs + national base price tables + regional multipliers + range reporting.

Source and assumptions

Data is built from public contractor cost benchmarks and common roofing labor patterns, then normalized into planner-friendly ranges.

• Last updated date is shown on each calculator page.
• 50 states are supported with national baseline intervals and region multipliers.
• Results are planning ranges for comparison, not final fixed quotes.

Core calculation flow

1. Normalize project scope and area into a base numeric model.
2. Apply material and complexity multipliers, then region multipliers.
3. Return low/average/high bands and explain key assumptions.
4. Use the result as a baseline for contractor quote comparisons.

Supported calculators:

Method update policy

We review methodology quarterly and update multipliers when regional market conditions materially change.

Current focus: Project inputs · Material and labor assumptions · State and city multipliers · Permit and contingency allowance.