Builders-Calc
iPhone / Utilitaires
No fractions? No good.
Builders-Calc is the only construction calculator in this price range with a native fraction keyboard. Tap ½" instead of typing 0.500. Built for people who work in feet, inches, and fractions — not decimal approximations.
— FRACTION KEYBOARD —
Every inches input has an ⅛ ¼ ⅜ ½ ⅝ ¾ ⅞ button row. Tap once to set the fraction. Tap 0 to clear. No typing. No rounding errors.
— FIVE CALCULATORS IN ONE —
LUMBER
• Board Feet — thickness × width × length with a quantity multiplier. Know exactly how many board feet you're buying before you leave the yard.
• Studs — enter wall length and height, choose 12"/16"/24" on-center spacing, and get stud count plus total linear footage for plates.
• Plywood — square footage plus waste percentage gives you the exact number of 4×8 sheets to order.
CONCRETE
• Slab — length, width, and depth in inches gives you cubic yards and bag counts for both 60 lb and 80 lb bags simultaneously.
• Footing — linear footage with width and depth in inches → cubic yards and bag counts.
• Post Hole — diameter, depth, and hole count → total cubic yards and bags. Run 12 fence posts and see the total in one tap.
ROOF
• Pitch Info — enter your X:12 rise and instantly see the angle in degrees, grade percentage, roof multiplier, and a plain-English slope description (e.g. "Moderate — most common residential").
• Rafter Length — horizontal run plus pitch → rafter length in both decimal feet AND feet/inches/eighths so you can mark it directly on the stock.
• Roofing Squares — building footprint plus pitch and waste percentage → plan area, actual surface area, squares, and bundle count.
STAIRS
• Enter total rise in feet, inches, and fractions using the fraction picker. Enter tread depth the same way. Get number of risers, riser height, total run, and stringer length — all in feet/inches/eighths.
• IRC Code Check flags automatically if your riser height exceeds the 7¾" maximum or your tread is below the 10" minimum.
CONVERT
• Feet & Inches — feet, whole inches, and fraction → decimal feet, total inches, meters, centimeters, and millimeters all at once.
• Metric — enter meters and get feet & inches (displayed as 6' 3½"), decimal feet, total inches, centimeters, and millimeters.
• Temperature — live Fahrenheit ↔ Celsius converter plus a concrete curing temperature reference chart (ideal range, cold weather warnings, hot weather precautions).
— WHO THIS IS FOR —
Carpenters, framers, concrete workers, roofers, stair builders, general contractors, and serious DIYers. Anyone who has ever groaned at a calculator app that only speaks decimal.
— NO NONSENSE —
• One-time purchase. No subscription. No ads. No in-app purchases.
• Fully offline. Works in basements, crawlspaces, and job sites with no cell signal.
• No account required. No sign-in. No data collected.
• Launches in under a second. Does math. Done.
— TECHNICAL —
Requires iOS 16.0 or later. iPhone only.
