Tools
Each tool runs entirely in your browser. It calculates only from the numbers you type and the formula shown on its page; nothing is sent to a server by the calculators.
Window-to-Wall Ratio Calculator
Glazing area ÷ gross wall area for up to four facades, in feet or metres. Useful for comparing facade options for daylight and heat gain.
U-Value to R-Value Converter (U-Factor, RSI & R-Value)
Convert between ft²·°F·h/BTU, m²·K/W, BTU/h·ft²·°F and W/m²·K, and total the R-values of layers in series.
Flooring Area & Box Estimator
Sum rectangular areas, add a waste allowance you choose and round up to whole boxes.
Drywall & Sheetrock Calculator
Estimate 4×8 and 4×12 drywall sheets, screws, joint tape, and joint compound (mud) needed for walls and ceilings with waste allowance.
Interior Paint & Primer Coverage Calculator
Calculate wall and ceiling paint and primer in gallons and quarts with door and window deductions, coats, and waste margin.
Concrete Slab & Footings Calculator
Calculate concrete for slabs and footings in cubic yards and 60 lb or 80 lb pre-mixed bags, with a waste allowance.
Roofing Shingle & Underlayment Calculator
Calculate roofing squares, shingle bundles, and underlayment rolls from roof dimensions and pitch.
Frequently asked questions
Are the building and design tools completely free to use?
Yes. All calculators on XayDung US are 100% free, run directly in your browser without requiring account registration, and send zero calculation data to remote servers.
What calculators are available for construction and architectural planning?
We offer the Window-to-Wall Ratio (WWR) Calculator for facade design and energy code compliance, the U-Value to R-Value Converter with series assembly summing, the Flooring Area & Box Estimator for floor takeoffs, the Drywall & Sheetrock Calculator for gypsum panels, the Interior Paint & Primer Coverage Calculator for wall coating takeoffs, the Concrete Slab & Footings Calculator for cubic yards and bag counts, and the Roofing Shingle & Underlayment Calculator for roofing squares, bundles, and underlayment rolls.
Do the calculators support both imperial and metric unit systems?
Yes. Every tool allows instant switching between imperial units (feet, square feet, BTU/h·ft²·°F) and metric SI units (metres, square metres, W/m²·K, RSI) with exact physical conversion constants.
Can I use these calculators on mobile devices?
Yes. All tools are designed with responsive layouts, accessible touch targets, and clear input labels optimized for both mobile phones and desktop browsers.