Estimator inputs
Example data table
| Scenario | Total area | Affected | Severity | Location index | Key scope | Estimated range |
|---|---|---|---|---|---|---|
| Rental refresh | 1,200 sqft | 55% | Cosmetic | 95 | Paint, flooring, minor electrical | $8,900 to $21,400 |
| Family home update | 1,800 sqft | 45% | Moderate | 100 | Paint, flooring, fixtures, kitchen refresh | $18,700 to $46,800 |
| Heavy renovation | 2,600 sqft | 75% | Major | 120 | Full baths, kitchen, HVAC replace, roofing | $78,000 to $182,000 |
Formula used
1) Affected area
Affected Area = Total Area × (Affected % ÷ 100)
2) Base scope cost (low/high)
For each line item: Cost = Quantity × Unit Rate (Low or High) × Multiplier
3) Multiplier
Multiplier = Property Factor × Severity Factor × Quality Factor × Complexity Factor × (Location Index ÷ 100) × (1 + Labor Adjust ÷ 100)
4) Add-ons
Add-ons = Subtotal × (Permits% + Disposal% + Overhead% + Contingency% + Tax%) ÷ 100
How to use this calculator
- Enter total area and the portion affected by repairs.
- Select severity, location index, quality, and job complexity.
- Enable scope items and add realistic quantities where needed.
- Set fees, overhead, and contingency based on project risk.
- Submit to view the range above the form, then export.
Project briefing article
Define scope before assigning ranges
A reliable repair budget starts with a clear scope boundary. Separate cosmetic work from functional repairs, then confirm which rooms, elevations, or systems are included. Use the affected percentage to represent the portion of total area that will receive material and labor. Example data: Total area 1,800 sqft, affected 45% results in 810 sqft of repair scope.
Understand what the multiplier represents
The multiplier consolidates market and project conditions into one adjustment. Location index reflects local labor and material costs, while severity, quality, and complexity model the effort required to deliver the work. Example data: Location 110 with premium finishes can increase the range meaningfully versus location 95 with economy choices.
Build the subtotal from line items
Line items are calculated using quantities and unit-rate ranges, then scaled by the multiplier. Area-based items like painting, flooring, and drywall use affected area. Count-based items like fixtures and electrical points use realistic counts from walkthrough notes. Example data: 3 plumbing fixtures and 12 electrical points often fit a moderate refresh.
Apply fees, overhead, and risk allowances
Add-ons convert a construction subtotal into a budget-ready range. Permits and disposal are frequently overlooked, overhead and profit align the estimate with contractor pricing, and contingency protects against hidden conditions. Example data: 12% overhead plus 10% contingency produces a stronger planning number on uncertain scopes.
Use outputs for planning and decision making
Review the low-to-high range alongside the per-square-foot values to compare options quickly. Tight ranges typically indicate well-defined scope and normal access. Wider ranges suggest unknowns or mixed specifications. Share results with stakeholders using the export buttons, then refine with quotes and detailed takeoffs as scope becomes firm.
FAQs
1) What does “location cost index” mean?
It scales the estimate to local market conditions. 100 represents an average baseline. Values above 100 increase the range for higher labor and material costs, while values below 100 reduce the range.
2) How should I choose the affected area percentage?
Use the portion of the building that will receive direct work. If only selected rooms are renovated, estimate their area versus total area. For unknown damage, start conservative and increase after inspection.
3) Why are there low and high costs for each line item?
Ranges reflect variation in specifications, site access, and labor productivity. The low value suits simpler work and standard materials. The high value captures premium selections, rework, or difficult conditions.
4) When should I raise contingency?
Increase contingency when scope is incomplete, concealed conditions are likely, or schedules are tight. Examples include older buildings, water damage, mold remediation risk, or unknown structural repairs found after demolition.
5) How do I estimate electrical points and fixtures?
Count outlets, switches, lights, and new connection points from a room-by-room review. For fixtures, count items being replaced or added, such as faucets, toilets, or valves. Use field notes for accuracy.
6) Should sales tax be included in the estimate?
Include tax if your budget must reflect the total out-of-pocket cost. If your quotes exclude tax or materials are tax-exempt, set it to zero. Always align with local rules and contract terms.
7) Is this suitable for final bids?
This tool is best for early planning and stakeholder alignment. For final pricing, confirm scope, perform takeoffs, obtain supplier quotes, and validate labor assumptions. Use the calculator to set expectations, then refine.