Insulation Replacement Calculator

Replace insulation confidently with instant, detailed totals. Set units, waste, taxes, and energy savings assumptions. Export results to share with crews and clients easily.

Project inputs
Adjust assumptions to match your jobsite and bid structure.
Enter a valid area.
Use net coverage area for replacement.
Keep inputs consistent for fair comparisons.
Thickness estimate uses typical R per inch.
Measured or assumed current performance.
Code target or design goal for the assembly.
%
Applies to material cost only.
Uses type and thickness to estimate materials.
Enabled when typical pricing is off.
/hour
Blended crew rate or installer rate.
m²/hour
Coverage installed per hour.
Adds demolition, bagging, and dump fees.
Use 0 for new installs with no removal.
total
Tipping fees, dumpster, hauling, etc.
Optional membrane or facing cost.
Ignored if vapor barrier is off.
Flat allowance for foam/caulk work.
Ignored if air sealing is off.
%
Applied before tax.
%
Set to 0 if tax is not applicable.
Energy savings assumptions (optional)
Changes how savings convert to bills.
/kWh
Use your utility rate for best accuracy.
Use local climate normals if available.
1.0 baseline; >1 for infiltration effects.
New
Example scenarios
Use these to sanity-check your inputs.
Case Area Existing Target Type Waste Labor rate Productivity Notes
A 60 m² R 13 R 30 Blown-in cellulose 8% 18 /hour 28 m²/hour Attic top-up with modest removal.
B 900 ft² R 7 R 21 Mineral wool 10% 22 /hour 220 ft²/hour Wall bays; slower access and cutting.
C 120 m² RSI 1.2 RSI 5.3 Polyiso rigid board 6% 20 /hour 18 m²/hour Exterior continuous layer; includes taping.
Formula used
These relationships drive the estimate.
  • Unit conversions: ft² = m² × 10.7639, R = RSI × 5.6783.
  • Thickness (estimate): Thickness(in) = Target_R / (R_per_in), then mm = in × 25.4.
  • Material cost: Material = Base × (1 + Waste%).
  • Labor hours: Hours = Area / Productivity, then Labor = Hours × Rate.
  • Subtotal: Subtotal = Material + Labor + Options.
  • Discount & tax: AfterDiscount = Subtotal − (Subtotal × Discount%), Total = AfterDiscount + (AfterDiscount × Tax%).
  • Energy savings (simple): ΔU = (1/Existing_RSI) − (1/Target_RSI).
  • Thermal energy saved: kWh_th = Area × HDD × 24 × ΔU / 1000, then adjust by a real-world factor.
  • Bill savings: convert kWh_th to kWh or therms using COP/efficiency, then multiply by your energy price.
  • Payback: Payback(years) = Total / AnnualSavings, when savings are positive.
Reminder: This is a planning tool. Assembly details, air leakage, moisture control, and workmanship can change real outcomes.
How to use this calculator
A quick workflow for realistic numbers.
  1. Measure the net area being replaced, then choose the correct unit.
  2. Enter existing and target thermal resistance using one unit system.
  3. Select the insulation type that matches your design or availability.
  4. Decide between typical pricing or a custom cost per area.
  5. Set waste, labor rate, and productivity based on access conditions.
  6. Toggle removal, vapor barrier, and air sealing if they apply.
  7. Optionally add degree-days and energy price for payback insight.
  8. Press Calculate, then export CSV or PDF for sharing.
Tip: Run two scenarios with only one change to see its impact.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.