About this calculator

Modern EU double-glazing has a U-value of ~1.2 W/m²K; triple glazing ~0.8; old single glazing ~5.7. Annual heat loss = U × area × HDD × 24 / 1000 kWh.

Frequently asked questions

What does the Window Glazing Area & U-value Cost Calculator do?

Glass area for a window and annual heat-loss cost by U-value (EU energy ratings). Modern EU double-glazing has a U-value of ~1.2 W/m²K; triple glazing ~0.8; old single glazing ~5.7. Annual heat loss = U × area × HDD × 24 / 1000 kWh.

Is the Window Glazing Area & U-value Cost Calculator free to use?

Yes. Every calculator on Calcurly.com is free, works in your browser without sign-up, and can be embedded on your own website.

How accurate is the Window Glazing Area & U-value Cost Calculator?

Results are calculated in real time using industry-standard formulas. Treat the output as a well-informed estimate — always cross-check with local regulations, product datasheets, or a qualified glazing & windows professional before committing to a purchase or a job.

What inputs does the Window Glazing Area & U-value Cost Calculator need?

Enter values for: Window width (m), Window height (m), U-value (W/m²K), Heating degree days, Energy price (€/kWh). Sensible defaults are pre-filled where possible so you can start with a single change.

Can I embed the Window Glazing Area & U-value Cost Calculator on my own website?

Yes — copy the iframe snippet at the bottom of this page, or use the Embed Generator to customise the size. The embedded version stays in sync with the live calculator on Calcurly.com.