The four inputs
1. Labor rates — Bureau of Labor Statistics
Trade-specific wage data comes from the BLS Occupational Employment and Wage Statistics (OEWS), May 2024 release. We use median hourly wages for the relevant SOC code and adjust by metro using OEWS metropolitan area data:
- Roofers: SOC 47-2181, median $25.80/hr
- Carpenters: SOC 47-2031, median $27.40/hr
- Electricians: SOC 47-2111, median $32.40/hr
- Plumbers: SOC 47-2152, median $30.85/hr
- HVAC technicians: SOC 49-9021, median $26.80/hr
- Sheet metal workers (gutters): SOC 47-2211, median $29.50/hr
- Solar PV installers: SOC 47-2231, median $24.60/hr
To convert wages to billable contractor labor rates, we multiply by 2.0–2.6× to cover insurance (general liability, workers comp), payroll burden (FICA, unemployment), overhead (vehicles, supervision, office), and profit. The multiplier varies by trade and local insurance market.
2. Material costs — RSMeans + distributor surveys
Material unit costs come from RSMeans 2025 Q4 construction cost data, validated against quarterly surveys of three national distributors (ABC Supply for roofing/siding/windows, Beacon Building Products for general supply, US LBM for lumber and structural). We use wholesale-channel pricing rather than retail home center pricing to reflect what contractors actually pay.
3. Regional multipliers — RSMeans City Cost Index + ZIP mapping
RSMeans publishes a quarterly City Cost Index (CCI) for 730+ US ZIP-3 prefix areas. We map ZIP codes to CCI values and apply the resulting multiplier to labor and overhead lines (material costs are largely uniform nationally). Sample multipliers:
- San Francisco (941): 1.45×
- New York (100): 1.42×
- Boston (021): 1.32×
- Chicago (606): 1.10×
- Atlanta (300): 0.96×
- Tulsa (741): 0.84×
4. Permit fees — city building department schedules
Permit fees are aggregated from individual city building department fee schedules, refreshed annually each January. Each estimate includes a permit fee appropriate to the project type and ZIP. Where city-specific data isn't available, we use state-level averages.
How they combine
For any given calculator, the published total is:
Total = (Materials × waste factor)
+ (Labor hours × loaded labor rate × regional multiplier)
+ (Equipment costs)
+ (Permit fees)
+ (Disposal / dumpster fees)
+ (Contractor margin: 9% – 15% of subtotal)The published high/low range (typically ±15%) accounts for project-specific variables we can't model directly: crew efficiency, accessibility, surprise scope (decking replacement, subfloor rot, hidden code violations), and finish-quality preferences.
Where calculators are not reliable
Three categories where our calculators are intentionally conservative or excluded:
- Custom or specialty work: Bespoke cabinetry, hand-glazed tile, custom millwork — pricing is too project-specific to model meaningfully.
- Disaster-zone pricing: Post-hurricane or post-wildfire markets see 30–80% premiums for 6–18 months. Our regional multipliers don't capture event-driven spikes.
- Premium-tier brands: When you go from "Andersen 100 series" to "Renewal by Andersen Fibrex," you're paying for a different business model, not a different product. The calculator handles standard brand tiers; for premium-brand pricing, see the relevant cost guide.
Update cadence
Material prices and BLS wage data: refreshed quarterly (March, June, September, December). RSMeans City Cost Index: refreshed quarterly. City permit fee schedules: refreshed annually each January. When a major code or refrigerant change shifts pricing — like the R-454B transition — we update the affected calculators within weeks.
Sources
- U.S. Bureau of Labor Statistics, Occupational Employment and Wage Statistics, May 2024 (oews.bls.gov)
- U.S. Bureau of Labor Statistics, Producer Price Index — Construction Materials
- RSMeans Construction Cost Data 2025, Q4 update
- RSMeans City Cost Index 2025 Q4
- National Association of Home Builders Building Materials Index
- U.S. Census American Community Survey, housing and construction estimates
- Individual city building department published fee schedules
- DSIRE database of state and federal renewable energy incentives
- ENERGY STAR product specifications and rebate finder
Corrections
Found a number that looks wrong? Tell us via the contact page. We log every correction request, verify against current data, and update affected calculators usually within 5 business days. Verifiable corrections occasionally surface a real industry shift before our quarterly refresh catches it.