JobRig Construction Calculator

JobRig is a construction calculator kit built for the trades: carpenters, framers, roofers, and every crew that works to an angle or lays out a run. Two tools, one keypad, and both draw the answer live as you type. Triangle is a right triangle calculator: enter sides, angles, roof pitch or slope in any order, and it solves the triangle. Spacing works out even spacing for balusters, rafters, joists, pergola beams and fence posts. No ads.

It exists because squaring, pitch, spacing and unit conversions kept living in different places. JobRig puts them in one app, a tap apart on the home screen.

TRIANGLE: RIGHT TRIANGLE SOLVER
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." Triangle solves the moment the numbers are enough, 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.
• Square-ups and diagonal 3-4-5 checks: corners dead-on 90°, on any scale.
• Roof pitch calculator: rise and run in, pitch out, in degrees, a slope percentage, or 6:12, on a rise:12 or rise:10 base.
• Rafter length from rise and run.
• Stairs and ramps from rise over run: stringer length and angle, ramp slope in degrees, percent, or a ratio like 1:12.
• Any triangle in Advanced: a wall on an angled boundary line gets its diagonal and the cut angles at each end. A dual-pitch roof gets both rafter lengths, and the drawing shows where the ridge lands.
• Area and perimeter readouts.
• Share the drawing as a PDF or image: send it to the crew or the client, or save it to your phone.

BALUSTER & EVEN SPACING CALCULATOR
Type the run and either how many members or how far apart, and Spacing works out the rest, counting the width of each member. Any two of run, count and spacing decide the third.
• Balusters and spindles, fence pickets, board and batten, deck boards, joists, rafters, slats and shelves: any run set out in equal bays.
• Spacing read between centres or as the clear span between members.
• Each end flush, or the same gap the members have between them. Advanced adds a gap you type yourself.
• Type a target spacing and it fits the nearest equal spacing at or under it.
• In Advanced, set a smallest and largest spacing and it picks the count. Step the count up or down and watch the spacing change.
• The layout is drawn with the run, the spacing and the end gaps marked on it.

Not in the trades? The same math covers DIY projects: slope from rise over run, a stair stringer's length and angle, a shed roof, evenly spaced fence posts.

UNITS LIKE YOUR TAPE
• Metric and imperial in both tools, including real tape-measure fractions like 5' 6 1/2".
• Pick your fineness, from 1/4" down to 1/64", or decimal feet or decimal inches when the plans read that way.
• Quick-fraction chips suggest the tape fraction you're likely to need next.
• Metric your way: mm, cm or m, with the decimal places you set.
• Hypotenuse calculator in feet and inches: the Pythagorean theorem the way your tape reads it, 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 what you want to change.
• Each tool keeps what you typed while you use the other.
• Keep-awake, haptics and key clicks, all optional, and dark, light or follow-your-phone themes.
• Undo after reset.

PRIVATE BY DESIGN
• 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.