Mold Remediation Cost Calculator

Most homeowners use this estimate to compare contractor quotes and avoid overpaying.

Real Cost Examples

• 100 sq ft bathroom: $1,000 to $2,500.
• 300 sq ft attic: $3,000 to $7,500.
• 500 sq ft basement: $5,000 to $12,000.

In many homes, basement mold removal cost trends toward the higher end when moisture issues and limited access are both in play.

Is This Cost Normal?

Low quotes are usually around $500 to $1,500 for small, visible areas with easy access. Average projects often land between $2,000 and $6,000. Once estimates move past $7,500, you are usually dealing with heavy containment, demolition, or large contaminated zones.

Pay attention when pricing is high but the scope is vague, the moisture source is not identified, or no verification testing is included. Still, higher quotes can be justified when mold is hidden in walls, spread through HVAC, or tied to structural repairs.

The cost to remove mold from a house increases quickly when contamination spreads across multiple rooms, reaches framing, or affects your duct system.

Pricing ranges are based on aggregated contractor estimates and industry cost data across the US.

How much does mold remediation cost?

Most homeowners see totals between $500 and $10,000 depending on scope, access, and severity. Small visible jobs can stay near the low end, while multi-room or structural cleanup lands higher. The calculator helps you pressure-test quotes before work begins, so pricing surprises are less likely.

How much does mold removal cost?

For most homes, mold removal cost is about $10 to $25 per square foot, depending on where the mold is and how deep it goes. A 300 sq ft attic usually lands around $3,000 to $7,500. If access is tight or contamination is heavier, quotes tend to rise.

Black mold remediation cost

Black mold (Stachybotrys) remediation typically costs 20% to 40% more than standard mold removal because it requires Level 3 containment, full PPE, and HEPA air scrubbing throughout the job. For a 200 sq ft area, expect $3,000 to $8,000 depending on severity. Many contractors charge a premium for black mold because disposal requirements are stricter and clearance testing must confirm spore counts are below safe levels before releasing the containment.

What should you do with this estimate?

Use this number as your baseline before you commit to a contractor. It helps you walk into quote calls with context instead of guessing.

• Compare contractor quotes against this range, not just the lowest price.
• Avoid unusually low bids that skip containment, cleanup steps, or follow-up testing.
• Expect variation when hidden mold shows up behind walls, under flooring, or inside ductwork.

How to Calculate Mold Remediation Cost

• Mold remediation cost typically ranges from $10 to $25 per square foot.
• Small projects: $500 to $2,500.
• Large projects: $5,000 to $10,000+.

What Affects Mold Remediation Cost

• Size of affected area.
• Mold type (black mold is more expensive).
• Accessibility difficulty, especially crawl spaces, finished basements, and steep attics.
• HVAC contamination, which can require duct cleaning and extra filtration.
• Containment level, from basic isolation to full negative-air containment.
• Labor and containment.

In real jobs, mold removal price usually jumps when access is tight and ducts are contaminated. Those two issues can raise the total cost to remove mold from a house well beyond what square footage alone suggests.

The mold remediation cost calculator runs in five quick steps. Each step takes about ten seconds, and the result shows a low-to-high cost range with a trade-by-trade breakdown.

1. Pick where the mold is growing. Each location carries a different per-square-foot range because access difficulty and typical damage patterns vary.
2. Enter the affected area in square feet. Use the preset buttons for common sizes or type your own. A bathroom wall is about 50 sq ft, a bedroom wall 80 to 120 sq ft, and a full attic 300 to 800 sq ft.
3. Choose the severity level. Surface mold on hard materials costs less because no demolition is needed. Severe mold through structural framing costs more because of containment, demolition, and rebuilding.
4. Check optional add-on services. Most professionals recommend pre-remediation testing and post-remediation clearance testing to verify success.
5. Click "Calculate cost" to see your estimate, breakdown, and typical timeline.

Pro tip: always fix the moisture source before starting mold remediation. I have seen homeowners spend $5,000 on mold removal only to have it return in six months because a roof leak or plumbing drip was never repaired. The remediation company should identify the moisture source as part of their assessment.

If you are comparing bigger projects, use our home addition cost calculator and renovation cost calculator to budget structural and finish work after remediation.

2026 mold remediation cost by location

These are the per-square-foot ranges the calculator uses, sourced from US national contractor surveys updated for 2026.

How this estimate works

This estimate starts with a location-based cost per square foot, then adjusts the range based on severity and selected add-ons. It gives you a practical planning number, not a binding quote.

• Cost per sq ft: each location uses a 2026 US range, usually $10 to $25 and up to $30 in harder conditions.
• Severity adjustment: surface issues stay near the low end, structural contamination shifts toward the high end.
• Add-ons: testing, duct cleaning, clearance, and moisture-control upgrades are added on top of base cost.

The mold remediation cost formula adjusts a per-square-foot cost range based on where the mold is, how severe it is, and what additional services you need.

Base cost calculation

Each location has a cost range in dollars per square foot. The calculator narrows that range based on severity:

• Surface/Minor: uses the lower 40% of the range. Surface cleaning with biocide, HEPA vacuuming, no demolition.
• Moderate: uses the middle 30% of the range. Some drywall or insulation removal, containment barriers, HEPA air filtration.
• Severe/Structural: uses the upper 30% of the range. Full containment with negative air pressure, structural material removal, rebuilding.

Example calculation

A 200 sq ft basement with moderate severity and post-remediation clearance testing:

• Basement range: $10 to $30 per sq ft
• Moderate severity narrows to the middle 30%: $18 to $24 per sq ft
• Base cost (low): 200 x $18 = $3,600
• Base cost (high): 200 x $24 = $4,800
• Clearance testing add-on: $200 to $400
• Total estimate: $3,800 to $5,200

This gives you a practical range to compare against contractor quotes for a mid-severity basement job.

For a full breakdown of what drives mold cleanup pricing, see our mold remediation cost guide.

Cost breakdown percentages

Labor accounts for about 60% of mold remediation cost because the work is manual, requires certified technicians, and involves strict containment protocols. Here is how a typical project breaks down:

• Labor (containment setup, cleaning, material removal): 60%
• Materials and supplies (biocide, antimicrobial, replacement drywall): 15%
• Equipment rental (HEPA air scrubber, negative air machine, moisture meters): 10%
• Containment and protection (plastic sheeting, tape, PPE): 10%
• Disposal and hauling (contaminated materials to landfill): 5%

When costs go higher

Costs move above the standard range when mold is hidden behind drywall or inside insulation, since crews need exploratory demolition before cleanup starts. HVAC contamination is another major driver because ducts can spread spores house-wide and need specialized cleaning. Insurance involvement can add documentation, inspection steps, and timeline delays. Failed remediation redo jobs also cost more because teams must remove missed contamination, rebuild containment, and run fresh verification testing.

As a ballpark, hidden cavity work can add $1,000 to $3,000, HVAC cleaning can add $300 to $1,000, and redo projects can increase total pricing by 25% to 50%.

Catching mold early saves thousands. Once it spreads behind walls or into HVAC systems, costs climb faster than most homeowners expect.

Common mistake: skipping post-remediation clearance testing to save $200 to $400. Without a third-party air sample confirming spore levels are back to normal, you have no proof the remediation worked. If you sell the home later, buyers and inspectors will ask for clearance documentation.