How cost calculators work
Audience: Everyone · 5 min
What they are
Trade-specific cost models at buildx.pro/costs: 2,182 calculators across 50 states, built from 8,712 tracked cost components (materials, labor tasks, permits, allowances).
How a number is produced
- Quantity formula. Each calculator defines how quantity is measured: per square foot, fixed per job, per unit, or percentage of material.
- Quality tier. Good, better, or best multiplies material and labor inputs. Pick the tier that matches the finishes you want.
- Regional multipliers. Labor rates and material costs adjust to your market. The same bathroom remodel prices differently in Austin and San Jose because crew rates and supply costs differ.
- Low/high range. Output is a range, not a point. Low assumes straightforward conditions; high covers surprises (access, rot, code upgrades).
How to use the result
- Treat the range as a negotiation anchor, not a bid. Send it to bidders and ask them to price the same scope.
- Ask what is fixed vs allowance, and what documented condition triggers a change order.
- Re-run with a different tier before cutting scope. Dropping from best to better finishes often saves more than shrinking the project.
Accuracy
Models are benchmarked against contractor-reported jobs and re-benchmarked in waves. They do not see your site, so hidden conditions (water damage, unpermitted prior work, panel capacity) move real bids. If your bid lands far outside the range, ask the bidder which line item diverges and why.