Cool Roof Calculator

Energy savings from reflective roofing surface.

Roof Area (sqft)

Current Roof SRI

New Cool Roof SRI

Annual Cooling Cost ($)

Annual Heating Cost ($)

Coating Cost ($/sqft)

Tab to move between fields

Net Annual Savings ($)

$273.00

≈ 5 tanks of gas

Cooling Savings ($/yr)$326.00

Heating Penalty ($/yr)$52.00

Peak Temp Reduction (°F)37

Installation Cost ($)$3,000.00

Payback Period (years)11

20-Year Net Savings ($)$2,468.00

How to Use This Calculator

Enter the roof area (sqft) and current roof SRI (Solar Reflectance Index).
Set the target cool roof SRI (white coatings: 82+, white TPO: 78+, white metal: 90+).
Enter your current annual cooling cost ($) and annual heating cost ($).
Review annual cooling savings, heating penalty, and net annual savings.
Check peak temperature reduction (F) -- every 10F reduction lowers cooling load ~5-10%.

How the result changes with New Cool Roof SRI

Roof Area (sqft): Total roof surface area in square feet.
Current Roof SRI: Solar Reflectance Index of existing roof. Dark asphalt ~20, aged white ~50.
New Cool Roof SRI: SRI of proposed cool roof coating. White elastomeric ~78-90, metal ~25-70.
Annual Cooling Cost ($): Current annual air conditioning electricity cost.
Annual Heating Cost ($): Current annual heating cost (gas or electric).
Coating Cost ($/sqft): Cost per sqft for cool roof coating application. Elastomeric ~$1-3/sqft.

Net Annual Savings ($): Annual energy savings after subtracting winter heating penalty.
Cooling Savings ($/yr): Estimated annual reduction in cooling costs.
Heating Penalty ($/yr): Increased winter heating cost from roof reflectivity.
Peak Temp Reduction (°F): Estimated peak roof surface temperature reduction.
Installation Cost ($): Total cost to apply the cool roof coating.
Payback Period (years): Years to recoup coating cost through energy savings.
20-Year Net Savings ($): Total savings over 20 years minus installation cost.

Identify Input Parameters
4 parameters
Roof Area (sqft) = 2000, Current Roof SRI = 20, New Cool Roof SRI = 82, Annual Cooling Cost ($) = 1500 = 6 input(s) provided
Calculate Net Annual Savings
Net Annual Savings = annualCoolingSavings - annualHeatingPenalty
273 = $273
Calculate Cooling Savings
Cooling Savings = annualCoolingCost * coolingReductionPct
326 = $326
Calculate Heating Penalty
Heating Penalty = annualHeatingCost * heatingPenaltyPct
52 = $52