Add 12′ 4-1/2″ to 3′ 9-3/4″.
Your phone's calculator cannot. This one can, and it does it in exact fractions, so a hundred cuts in a row never drift.
3′ 9-3/4″
16′ 2-1/4″ One step. Not six conversions on a ladder with gloves on.
What it does
Feet, inches, fractions
1/2 – 1/32Add, subtract, multiply, divide. Parentheses, so you write the calculation the way you think it. When a result cannot be written at your precision it says so instead of rounding in silence.
Five units at once
ft-in · mm · mEvery answer in feet-inches, decimal feet, decimal inches, millimetres and metres. Tap one and the display changes; the measurement does not.
A tape that remembers
per jobEvery calculation saved under the job it belongs to, with the expression that produced it. Label a line, tap it to bring it back, email the whole job as a PDF or a CSV.
Eight trade calculators
stairs · roof · concreteStairs with a code warning when a riser runs over. Rafters, plumb and seat cuts. Concrete in cubic yards and bags. Tile, drywall, paint, lumber, board feet, area of any shape.
Built for a site
60 points minimum
Every key, so it works with gloves on. There is a left-hand layout.
No signal needed
Nothing in the calculator touches a network. It works in a basement.
No account
Nothing to sign up for. Your measurements never leave the phone.
Bought once
No subscription, no renewal, no ads. Pay once and it stays yours.
Get it
TrueRule is on the App Store for iPhone and iPad. The free version includes four of the eight trade calculators, ten lines of tape and three jobs. One payment unlocks the rest, for good.