Window U-Value and Energy Savings Calculator
Compare single, double, and triple pane windows with different frame types.
Estimate heat loss and potential energy savings for your home.
Window Energy Analysis
Window U-Value measures how well a window insulates. Lower U-values mean better insulation.
Heat Loss (BTU/hr) = U-Value × Area × Temperature Difference
Annual Heat Loss (BTU) = Heat Loss per hour × Heating Degree Hours
Typical U-Values by window type:
| Window Type | U-Value (Imperial) | R-Value |
|---|---|---|
| Single pane, wood frame | 1.04 | 0.96 |
| Single pane, aluminum frame | 1.27 | 0.79 |
| Double pane, wood frame | 0.49 | 2.04 |
| Double pane, vinyl frame | 0.46 | 2.17 |
| Double pane, Low-E, vinyl | 0.32 | 3.13 |
| Triple pane, Low-E, vinyl | 0.19 | 5.26 |
Frame type impact:
- Aluminum: Conducts heat rapidly — worst insulator
- Wood: Natural insulator — good performance
- Vinyl: Similar to wood — low maintenance
- Fiberglass: Best overall thermal performance
Energy savings are calculated by comparing heat loss between your current windows and an upgrade option, multiplied by local energy cost.