Updated September 29, 2026 by Chris Horton. Interactive decoder for the NFRC label, not an energy score. How we estimate costs
For homeowners with an NFRC label in front of them — on a window, door or skylight they are buying, verifying at delivery, or checking against a quote. Five steps. At the end you get every rating on the label explained, placed in a performance band, and marked against the climate zone you picked. Fields that are not on the label are marked UNKNOWN, not filled in with defaults. The tool does not compute an overall energy score. NFRC does not publish one and neither do we.
Enter every rating exactly as printed on the label. Where a rating is not on your label, leave the field blank: NFRC does not require every rating on every label, and a blank field becomes an UNKNOWN row in the result, not a guess. The decoder does not invent a rating that is not on the paper.
NFRC publishes a different label for doors than for windows. On a window label there are up to five ratings (U-factor, Solar Heat Gain Coefficient, Visible Transmittance, Air Leakage, Condensation Resistance). On a door label there are two (U-factor and Solar Heat Gain Coefficient) tied to the door’s glass configuration, in NFRC’s own description of the door label. Pick the label type in step 1 and the tool asks for the correct fields.
Step 1 of 5 · The label in front of you
The label in front of you
Which label, and where the product will live.
Core ratings on the label
Type each number exactly as printed. Leave blank if the rating is not on your label. Do not round.
Optional ratings on the label
NFRC does not require these on every label. Blank means the rating is not printed on your label, which the result records as UNKNOWN.
Context around the number
What the number is being compared against changes what the number means.
What the label tells you
Ratings, decoded
Read as is the general performance band. Zone note places the number against how homeowners in your zone typically use it. UNKNOWN means the rating was not on the label you entered.
Fields not on the label
Questions worth asking
Nothing is stored. This runs in your browser and resets when you close the page. Verify current ENERGY STAR thresholds at energystar.gov — they change across versions.
This tool needs JavaScript. The framework is explained in our doors standards guide.
What this tool does, and what it does not
It can help you
- Explain what each rating on the NFRC label measures.
- Place your number in a general performance band.
- Add a zone note based on the ENERGY STAR climate region you picked.
- Mark ratings not on your label as UNKNOWN rather than assumed.
- Surface the questions worth sending to the supplier or manufacturer.
It cannot tell you
- An overall energy score. NFRC does not publish one and neither do we.
- Whether a product qualifies for a specific ENERGY STAR version. Verify current thresholds at energystar.gov.
- Whether the label is authentic. Cross-check the CPD Product ID against the NFRC Certified Product Directory.
- Whether a product will meet your local energy code. Codes are set by state and jurisdiction.
- Federal tax-credit eligibility. Use the IRS 25C rules and your product’s current ENERGY STAR status.
Where to go next
- Doors: ENERGY STAR and NFRC label requirements.
- Window Warranty Checker.
- Window Quote Analyzer.
- Compare Window Quotes.
- Insert vs Full-Frame Windows.
- All windows guides and how we estimate costs.
About the author
Chris Horton writes UpgradeWorth’s homeowner decision guides. He covers how replacement projects are scoped, quoted and warrantied, with a bias toward what a homeowner can verify in writing rather than what a salesperson says at the kitchen table. UpgradeWorth does not sell leads, rank contractors or accept placement fees.