Contractor Insurance Cost Calculator
Estimate your annual contractor insurance premiums based on trade type, revenue, payroll, and coverage needs.
Formulas Used
General Liability:
GL Premium = (Annual Revenue ÷ 1,000) × Trade Rate × Limit Multiplier
Trade rates range from $5.80 (landscaping) to $14.50 (roofing) per $1,000 revenue.
Limit multipliers: $1M/2M = 1.00×, $2M/4M = 1.25×, $5M/10M = 1.65×. Minimum: $750.
Workers' Compensation:
WC Premium = (Annual Payroll ÷ 100) × NCCI Class Rate × State Multiplier
Class rates range from $5.00 (HVAC) to $18.00 (roofing) per $100 payroll.
State multipliers: Low = 0.80×, Mid = 1.00×, High = 1.45×. Minimum: $500.
Tools & Equipment (Inland Marine):
Tools Premium = Insured Value × Trade Rate (1.8% – 3.0%). Minimum: $200.
Claims Surcharge:
Applied to GL + WC: 0 claims = 0%, 1 = 10%, 2 = 20%, 3+ = 35%.
Total: GL + WC + Tools + Claims Surcharge
Assumptions & References
- GL rates based on ISO/NCCI commercial general liability rating methodology for contractor classes.
- Workers' comp rates derived from NCCI class codes: 5183 (plumbing), 5551 (roofing), 5190 (electrical), 5645 (carpentry), etc.
- State WC multipliers reflect average filed rates; high-cost states include CA, NY, WA, NJ; low-cost include TX (non-subscriber), NC, IN.
- Tools & Equipment rates based on inland marine market averages (ISO Contractors Equipment form).
- Claims surcharge reflects typical experience modification factor (EMR) impact on GL and WC.
- Subcontractor payroll is excluded from WC calculation; separate certificates of insurance should be obtained from subs.
- Does not include: Commercial Auto, Professional Liability (E&O), Umbrella/Excess, Builder's Risk, or Surety Bonds.
- Estimates are illustrative. Actual premiums depend on insurer underwriting, loss history, project types, and state filings.
- Sources: NCCI (ncci.com), ISO (verisk.com), IRMI Contractor Insurance Guide.