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Free construction calculators & tables
A working feet-inch-fraction calculator and 399 ready-made lookup pages — fraction conversions, roof pitch, stud layout — every number computed by the same exact engine the TapeMath app ships.
Start here
Feet-inch-fraction calculator
Add, subtract, multiply, divide & convert — free, in your browser
Inch fraction → decimal
Every 1/64 to 63/64 · 63 pages
Inches → feet & metric
1 to 120 inches · 120 pages
Add inch fractions
Common sixteenths & eighths · 120 pages
Roof pitch → degrees
1/12 to 24/12 · 24 pages
Stud & joist layout
12"–24" on center · 72 pages
Why the numbers are trustworthy
Every value here is produced by the very engine the iOS app runs on — exact fraction arithmetic on whole-number sixteenths, not floating-point estimates. The browser build is checked digit-for-digit against the app's Swift engine over tens of thousands of randomized calculations, so what you read online is exactly what the app shows on the jobsite.
The same math, offline
Every calc, on your tape measure — even with no signal.
TapeMath for iPhone runs this exact engine offline, adds rafters, stairs, studs, pitch and a paperless tape, and the key layout your thumbs already know. $9.99 once — no subscription, ever.
See the appComing soon — TapeMath is in final App Review. Meanwhile, use the free web calculator →