Lumber Calc

Lumber Calc is a free site of lumber, deck, stair and rafter calculators for DIYers, hobbyists and small contractors. It covers board feet, stairs and stringers, deck boards, balusters, fences, siding, studs, cut lists, rafter length and roof pitch.

It offers a diagram, an optional IRC or DCA 6 code check and a printable shopping list, in imperial and metric. No account is needed, inputs stay in your browser and there is no cloud save. No paid tiers are listed. It is web only, and the page says it does not provide stamped drawings, inspection approvals or manufacturer specs.