Project inputs
Example data table
These sample scenarios illustrate how options can change totals.
| Area (sq ft) | Severity | Location | Containment | Testing | Drying | Estimated Total |
|---|---|---|---|---|---|---|
| 120 | Light | Bathroom | Minimal | No | 0 days | $1,250 – $1,690 |
| 350 | Moderate | Basement | Standard | Yes | 3 days, 2 units | $5,900 – $7,980 |
| 900 | Heavy | Crawlspace | Full | Yes | 5 days, 4 units | $20,400 – $27,600 |
Formula used
1) Core remediation subtotal
Core = Area × BaseRate(severity) × LocationMultiplier × AccessMultiplier × ContainmentMultiplier
2) Add-ons and allowances
Add-ons include setup, testing, HVAC cleaning, demolition, antimicrobial work, odor treatment, drying rentals, repairs, disposal, travel, and permit/documentation allowances.
3) Overhead, profit, and emergency surcharge
Direct = Core + Add-ons
Overhead = Direct × (Overhead% ÷ 100)
Profit = (Direct + Overhead) × (Profit% ÷ 100)
Emergency = (Direct + Overhead + Profit) × (Emergency% ÷ 100)
Total = Direct + Overhead + Profit + Emergency
A planning range is shown as Total ±15% to reflect site variability.
How to use this calculator
- Enter the affected area in square feet, including suspected spread.
- Select severity, location, access, and containment for the work zone.
- Choose whether to include testing, HVAC cleaning, demolition, and antimicrobial work.
- If drying is needed, enter equipment days and dehumidifier count.
- Add allowances for repairs, disposal, travel, and documentation as required.
- Set overhead, profit, and any emergency surcharge to match your pricing model.
- Press Calculate Cost to view totals and the breakdown, then export CSV or PDF.
Professional budgeting notes for mold remediation
1) Start with moisture control and scope
Mold costs rise when moisture is still active. Confirm the source: leaks, condensation, drainage, or HVAC issues. Define the work area by visible growth plus nearby materials with staining or high moisture. Clear scope prevents change orders and supports a realistic schedule. Document photos and readings for records.
2) Typical price bands used for planning
Price guides often quote professional remediation around $10 to $25 per square foot, with many projects landing in the low-thousands. Rates increase when access is difficult or containment is upgraded. Use ranges early, then refine after inspection and moisture readings. For budgeting, pair unit rates with a mobilization minimum so small jobs are not underpriced.
3) Area tiering improves decision making
Guidance commonly groups jobs as small (under 10 sq ft), medium (10–100 sq ft), and large (over 100 sq ft). Larger areas add engineering controls, negative pressure, and more documentation. This calculator scales setup, testing, and management allowances with total area.
4) Containment and worker protection
Containment is a major swing factor after square footage. Minimal barriers can fit localized surface cleaning, while full containment may require poly walls, HEPA filtration, and decon zones. Higher containment increases time, consumables, and equipment, especially in crawlspaces and attics.
5) Demolition, cleaning, and rebuild allowances
Remediation is not only “wipe and spray.” Porous materials like drywall, insulation, and carpet often require removal. After cleaning, surfaces may need sealing, patching, and repainting. Keep remediation and reconstruction separate, or add a repair allowance for clarity.
6) Drying equipment and downtime costs
When materials are wet, drying drives cost through days on rent. Dehumidifiers, air movers, and monitoring visits add daily charges, and delays can impact other trades. Enter drying days and unit count, then compare alternatives like targeted removal and better ventilation.
7) HVAC, air quality, and clearance testing
If spores may have moved through ductwork, HVAC cleaning and filter upgrades are common. Clearance testing adds sampling and reporting but reduces disputes and rework. This tool includes optional testing and HVAC allowances so proposals match contract expectations.
8) Using the breakdown to control total cost
After calculating, review the breakdown line by line. Adjust containment, demolition, drying, and testing based on risk and specifications. Keep overhead and profit visible so clients can compare bids fairly. Disciplined scope, documented moisture control, and clear allowances deliver better outcomes.
FAQs
1) What area should I enter if mold is behind drywall?
Use the suspected impacted footprint, not only the visible spot. If staining suggests hidden spread, include adjacent wall bays or ceiling sections likely to be opened during demolition. Update the area after inspection reveals the true extent.
2) How do I choose a severity level?
Light fits small, surface-level growth with minimal material loss. Moderate suits typical room-scale issues. Heavy fits widespread colonization, repeated wetting, or multiple materials affected. High-risk applies when strict containment, higher PPE, or complex procedures are required.
3) When is full containment appropriate?
Choose full containment for larger areas, sensitive occupants, heavy contamination, or projects requiring negative pressure and decontamination steps. It is also common when the work zone connects to living spaces, returns, or shared building pathways.
4) Should I always include clearance testing?
Testing is often requested by owners, property managers, or insurers. It adds cost but provides documentation and confidence that cleaning met expectations. For small, simple jobs it may be optional, while larger projects frequently benefit from it.
5) Why does HVAC cleaning change the estimate so much?
Duct access, system size, and required containment can vary widely. If spores entered supply or return paths, cleaning, filter upgrades, and coil maintenance may be specified. Include it when air distribution could spread contamination beyond the work zone.
6) What does the repair allowance cover?
It covers patching and basic finishes after demolition, such as drywall repairs, primer, paint, trim touch-ups, or minor flooring transitions. For full reconstruction, create a separate rebuild estimate so remediation and restoration costs stay transparent.
7) Is the cost per square foot always reliable?
It is a useful benchmark, but not a guarantee. Access limits, containment, moisture conditions, and documentation requirements can change productivity. Use unit cost to compare scenarios, then rely on the full breakdown for final budgeting.