Construction calculators

Stair Calculator

Calculate stair layout from total rise: riser count, riser height in carpenter fractions, tread run, stringer length, and angle — checked against IRC limits.

Concrete Calculator

Calculate how much concrete a slab, footing, wall, column, or post hole needs in cubic feet and cubic yards, plus how many 40, 50, 60, or 80 lb bags to buy.

Board Foot Calculator

Work out board feet for lumber from actual thickness, width, and length, with a rough-sawn quarter-thickness shortcut, waste allowance, and cost estimate.

Asphalt Calculator

Estimate tons of hot mix or recycled asphalt for a driveway, lot, or base repair from paved area and compacted depth, with an optional material cost estimate.

Topsoil Calculator

Work out cubic yards, weight, and bag count for a lawn, garden bed, or raised bed from its shape, area, and fill depth, with soil-texture density presets sourced from USDA soil science.

Conduit Fill Calculator

Check whether a set of THHN/THWN-2 conductors fits inside an EMT, IMC, RMC, or PVC conduit under the NEC Chapter 9 fill limits, and see the smallest size that would pass if it does not.