JobRig: Triangle Calculator

JobRig

About this app

JobRig is a right triangle calculator built for the trades: carpenters, framers, roofers, and every crew that works to an angle. It fits the job instead of making the job fit it: enter sides, angles, roof pitch or slope in any order, and JobRig solves and draws the triangle live as you type. No ads.

It exists because three everyday jobs kept living in three different places: squaring a layout, turning rise and run into a slope or a pitch, and converting between units. JobRig puts all three in one tool.

WHAT IT DOES
Enter what you know: two sides, a side and an angle, a run and a pitch, in any order, straight off the tape. No fixed boxes, no "enter side A first." JobRig solves the moment the numbers are enough and redraws the triangle as you type, so you can find a missing side, the hypotenuse, or an angle from whatever you have. When a layout has two valid answers (the ambiguous SSA case), it shows both and a swipe compares them. Basic mode keeps it to the everyday right angle; Advanced mode opens the full triangle: a trig solver when you need one.

FOR THE JOBSITE
• Square-ups and diagonal 3-4-5 checks: corners dead-on 90°, walls and floors square, on any scale.
• Roof pitch calculator: rise and run in, pitch out, in degrees, a slope percentage, or 6:12. One tap converts degrees to pitch and back, on a rise:12 or rise:10 base.
• Rafter length from rise and run: clean right-triangle rafter math.
• Stairs and ramps from rise over run: stringer length and angle, ramp slope in degrees, percent, or a ratio like 1:12.

Not in the trades? The same math covers DIY and home projects: slope from rise over run in degrees or a slope percentage, a stair stringer's length and angle, a shed roof, a true square corner.

ADVANCED MODE FOR ANY TRIANGLE
The common case first: a deck or a wall that follows an angled boundary line. Enter the two sides and the angle between them, and JobRig returns the diagonal and the cut angles at each end. Or a dual-pitch roof: the building width as the base, a different pitch each side. It solves both rafter lengths, and the drawing shows where the ridge lands. Same keypad, same live drawing: any triangle you can measure enough of, the solver can finish.

MEASURE LIKE YOUR TAPE
• Metric and imperial, including real tape-measure fractions like 5' 6 1/2".
• Pick your fineness, from 1/4" down to 1/64", or switch to decimal feet or decimal inches when the plans read that way.
• Quick-fraction chips suggest the tape fraction you're likely to need next: one tap and it's in.
• Metric results your way: plain numbers or labelled mm, cm, or m, with separate decimal-place settings for sides and angles.
• Pythagorean theorem in feet and inches: two sides in, the diagonal out, the way your tape reads it.
• Hypotenuse calculator, tape style: the diagonal in tape fractions or decimals, ready to mark.
• US and European number formats.

MADE FOR THE FIELD
• Big, glove-friendly keypad, one-handed by design, with a left-handed mirror option.
• Tap the drawing itself to pick the side or angle you want to change.
• Keep-awake option so the screen stays on while you work.
• Dark, light, or follow-your-phone themes.
• Haptic and key-click feedback, three levels each, all optional.
• Area and perimeter readouts, tap to cycle their units.
• Share the drawing as a PDF or image: send it to the crew or the client, or save it to your phone.
• Undo after reset.

PRIVATE BY DESIGN
Part of the design is what JobRig deliberately does not do:
• No ads.
• Works offline: the math never needs a signal, and the app only needs to reach the internet about twice a year to confirm your version is still supported.
• No history: your measurements stay on your phone, and go somewhere only when you share or save a drawing yourself.

More trade tools are on the way, each added only when it can be done without complicating the tool in your hand. This release ships the right-triangle solver, done properly.

What’s new

Better performance on older phones.
Bug fixes.
We have updated our privacy policy.