Layout calculators — stairs, rafters, railings and floors

Divide the rise into even risers, lay out the notches, and check the result against the code.

Rail length and angle for a straight flight, the plumb and level cuts, and the IRC height, grip and guard checks.

Ramp length from the rise at 1:12 or gentler, with the runs, landings and handrails, checked against the ADA Standards.

Even gaps across any span, checked against the 4-inch guard rule, with tape-measure marks that don't drift.

Even picture-frame boxes across a wall, drawn as an elevation with the cut lengths underneath.

Even batten spacing across an accent wall from the spacing you want, the marks from one corner, the boards to buy, and a true-size spacer to print.

Common, hip and jack rafters for any pitch, with the birdsmouth laid out and the cut angles alongside.

Hip rafter length, pitch and cuts for a hexagonal or octagonal gazebo, where the hips land on the king post, and the posts and beams under them.

Rise and run, x/12, degrees or a rise over a span turned into all the others, with the slope multiplier and the plumb and seat cuts.

Top chord, bottom chord and web lengths and angles for a king post, queen post or Fink truss — the geometry, not the engineering.

How many rows, how wide to rip the first one, and where the end joints fall so they never line up.

Full tiles across the middle and a sized cut tile at every edge, centred or started from one wall.

Hole count and marks down a cabinet end panel, on the 32mm system or a plain 1" pitch.

Post count and the actual on-centre spacing for any run and maximum span.

The rough opening from the slab or window unit, its jambs, shims and floor, and where the king and jack studs and your header go around it.