Keld
Rafter lengths, stair stringers, board feet, concrete. The calculations a tradesperson runs every day — right the first time, and free to use right here.
No account. Nothing to install. Nothing you type leaves your browser.
Calculators
Pitch to angle, slope factor, and common rafter length with the ridge deduction and tail.
Open the calculator →Equal risers from a total rise, with tread depth, total run, stringer length and the 2R+T check.
Open the calculator →Board feet from nominal dimensions, for one piece or a whole order.
Open the calculator →Slabs, continuous footings and round piers in cubic yards, with waste and bag counts.
Open the calculator →Hip length, hip angle, and the common difference that steps every jack rafter down.
Open the calculator →Miter and bevel settings for sprung moulding cut flat, at any spring and corner angle.
Open the calculator →Multiplier, distance between bends, and the shrink to take off the measurement.
Open the calculator →True offset, travel and run when a pipe moves up and sideways at once.
Open the calculator →Bar count both ways, total linear feet and weight, for a slab mat at your spacing.
Open the calculator →Studs, plates and sheathing for a straight wall — with what is deliberately left out.
Open the calculator →Footprint and pitch to roof area, squares and bundles, with waste.
Open the calculator →Total fall over a run, in inches per foot, percent or ratio — all three at once.
Open the calculator →The app
The calculators on this site are the app's functions running in a browser. The app is the same maths on your phone, built for the place the work actually happens: offline, because basements and steel buildings have no signal, and quick enough to use with gloves on.
Keld is in build now, for iOS and Android. Until it ships, everything on this site is free and needs no account.
Use the calculators nowReference
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