Cost Calculator AI
Construction & ContractorsContractor Bid Builder

Construction Estimate Calculator

Build professional contractor estimates combining raw materials, subcontracts, in-house labor, overhead markup, and target profit margin.

Calculation Results

Contractor Estimate Bid Formula

Final Bid = (Direct Costs × (1 + Overhead % / 100)) / (1 - Target Profit Margin % / 100)
  • Direct Costs: Raw materials, subcontractor invoices, in-house hourly labor wages, and permit expenses.
  • Overhead Markup: 10%–15% applied to direct costs to cover insurance, office rent, vehicles, and equipment.
  • Profit Margin: Target net business return calculated as a percentage of final revenue.

Step-by-Step Worked Example

Scenario: Bidding an addition with $40,000 in materials, $25,000 in subs, 120 in-house labor hours at $50/hr

Calculation Steps:

  1. Total Direct Costs = $40,000 + $25,000 + $6,000 + $2,500 = $73,500
  2. Overhead Cost (10%) = $73,500 × 0.10 = $7,350
  3. Cost with Overhead = $73,500 + $7,350 = $80,850
  4. Final Bid Estimate = $80,850 / (1 - 0.15) = $95,117.65
  5. Gross Profit = $95,117.65 - $80,850 = $14,267.65
Result: The recommended bid proposal is $95,118, delivering a 15% net profit margin ($14,268) after covering $7,350 in company overhead.

How to Use This Calculator

  1. 1Enter all direct material, sub, and in-house labor costs.
  2. 2Specify company overhead percentage and desired net profit margin.

Assumptions & Limitations

  • Estimates are based on standard national averages and current prevailing construction materials and contractor rates.
  • Actual trade bids may fluctuate according to local building code requirements, permit fees, and site topography.
  • Always obtain multiple written bids from licensed, bonded, and insured contractors before commencing work.

Frequently Asked Questions

Why divide by (1 - Margin) instead of multiplying by (1 + Margin)?

Profit margin is calculated as Profit / Revenue. If you simply multiply cost by 1.15, your margin will only be 13.04%. Dividing by (1 - 0.15) ensures you achieve an exact 15% margin on final contract revenue.

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