Estimate potential cooling cost savings from home window film. The result is a scenario built from your inputs and assumptions — not a guarantee or a building-energy simulation.
Average monthly air-conditioning cost ($ per month) — use the cooling portion, not your whole electricity bill. Months using AC (0–12, illustrative default 4). Cooling share from treated windows (%, illustrative default 20). Window solar heat reduction (%, illustrative default 40).
Detailed estimate and BTU demonstration modes are also available. Free · No email required. Created by Shore Window Tinting / Shore Tint & More, Inc. Last updated October 1, 2026.
Start with the part of your electricity cost that goes to air conditioning, not the whole bill. Multiply it by the months you run AC to get a cooling-season budget.
Then estimate how much of that cooling cost comes from sun through the windows you plan to treat, and how much the film reduces total solar heat gain through those windows. Multiplying the two gives the share of the cooling budget the film could plausibly affect.
Monthly air-conditioning cost: $150 (the cooling portion only). Months using AC: 4. Seasonal cooling budget: $150 × 4 = $600.
Cooling share from treated windows: 20% — the part of that $600 caused by solar heat through those windows. Window solar heat reduction: 40% — how much the film lowers total solar heat gain through them.
Modeled cooling budget reduction: 20% × 40% = 8%. Estimated cooling-season savings: $600 × 8% = $48, leaving $552. All four numbers are illustrative assumptions, not measured household data.
A film that cuts solar heat gain by 40% does not cut your electric bill by 40%. Only part of your bill is cooling, and only part of cooling comes from sun through the treated glass. That is why the calculator multiplies the two percentages instead of using either one alone.
Solar Heat Gain Coefficient (SHGC) is the fraction of solar energy striking a window that ends up indoors, including sunlight passing straight through and heat the glass absorbs and releases inward. It runs from 0 to 1; lower means less solar heat.
If you know matched SHGC values for the same glass before and after film, the solar heat reduction is (before − after) ÷ before. For example, 0.60 to 0.35 is about a 42% reduction. Infrared rejection, TSER or a meter reading are different numbers and should not be entered as this value automatically.
Climate, which way the windows face, shading from trees and overhangs, the existing glass, how long the AC runs, its efficiency and your electricity rate all change the result. That is why the calculator asks for your numbers instead of applying a regional or national multiplier.
You can use this calculator to model 3M residential window film when you have matching film-on-glass SHGC ratings for your glass, before and after. Enter them in the Detailed estimate, or use the SHGC helper in the Quick estimate to work out the solar heat reduction.
A brand name alone does not set the savings: the same film performs differently on different glass, and the 40% default is an illustrative assumption, not a 3M rating. This is Shore Tint & More's independent tool, not an official 3M calculator or a manufacturer-endorsed prediction.
Handheld solar meters such as the EDTM SP1065 and SP1080 read radiation passing through glass in BTU/(h·ft²) or W/m². They do not capture heat the glass and film absorb and pass inward, so a meter percentage is not total heat rejection or bill savings. A heat-lamp demo is relative only. The BTU demonstration tab shows the reading change and never converts it to dollars.
It can reduce the cooling portion of an electric bill when sun through the treated windows adds meaningfully to air-conditioning load. The effect depends on climate, window exposure, existing glass, the film's rated SHGC and how much you use AC. It does not reduce fixed fees, water heating or other electricity use.
There is no universal percentage. Use the calculator with your own cooling cost, months of AC, the share of cooling caused by sun through the windows you'll treat, and the film's solar heat reduction. For example, $150 a month for 4 months with 20% and 40% gives $48 for the season — an illustration, not a typical or promised result.
No. Enter only the air-conditioning portion. If you are not sure, the optional bill-difference helper subtracts a mild-weather month from a summer month as a rough guide; other changes in usage or rates will affect that difference.
No. The quick estimate uses costs and percentages. A meter reading shows direct transmitted radiation at one moment, which is not the same as total solar heat reduction, so it should not be entered as the reduction percentage.
Solar Heat Gain Coefficient is the fraction of solar energy striking a window that ends up indoors, from 0 to 1. Matched before-and-after SHGC values for the same glass give the solar heat reduction: (before − after) ÷ before.
Yes, if you have matching film-on-glass SHGC ratings for your specific glass before and after the 3M film. Enter them in the Detailed estimate or the Quick estimate's SHGC helper. Don't apply the illustrative 40% default as a 3M figure. This is an independent Shore Tint & More tool, not an official 3M calculator.
This calculator covers the cooling season only. In winter, film that blocks solar heat can also reduce helpful sun, which may increase heating use and offset some cooling savings over a full year. Low-E insulating films change heat loss differently; ask about your specific glass.
No. It is a scenario using your inputs and labeled assumptions. It ignores thermal storage, HVAC part-load behavior and winter heating, and it does not predict a specific bill, payback or return on investment.
Request a free estimate or call (302) 947-4624. Shore Tint & More (Delaware Window Film) — 3M Authorized Dealer, IWFA accredited, serving Delaware and the Maryland Eastern Shore since 1989.