Window calculators & converters
Free, no-signup tools for US builders and architects working with European windows - unit conversions and cost estimates I reach for on real projects.
U-Factor to R-Value Converter
Convert a window U-factor to its R-value and back, with typical single, double, and triple-glazed values.
Open tool →U-Value to U-Factor Converter
Convert European metric U-value (W/m2K) to US imperial U-factor - the spec check every import project needs.
Open tool →European Window Cost Estimator
Enter your areas and get a live landed-cost range across three tiers, duties and freight included.
Open tool →