Woodwork calculators that draw the answer.
Board feet, stair stringers, rafters and decks, worked out from your numbers and drawn to scale. Answers come in tape-measure fractions, with the code limits next to them.
Nine calculators, grouped by the job in front of you.
Each one returns something you can build from: a cut list, a layout, a shopping list. The results link to the next calculation in the same project, so a deck leads to its stairs and a stair leads to its stringers.
Stairs & decks
Lay out a stair that passes inspection, then figure the decking, joists and screws.
Roof & wall framing
Pitch, rafter length and cut angles, and the studs, plates and headers for a wall.
Shop projects
Price hardwood by the board foot and mix the right amount of resin for a pour.
Finish carpentry
Even batten spacing across a wall, without the math on scrap cardboard.
Every answer comes back as a shop drawing.
A number on its own doesn't tell you whether the stair fits the room. This is what the stair calculator returns for a 9-foot floor-to-floor, marked up.
- Fractions you can find on a tape7 11/16″, not 7.714. Switch to millimetres from the header and your inputs convert with you.
- Code limits, cited by sectionEach riser is checked against IRC R311.7.5.1. Where the code answers with a table, we send you to that table.
- The part you cut is tintedGreen marks what the calculator is about: here the stringer, elsewhere the rafter or the resin.
- A title block that keeps your numbersEvery plate is stamped with the result it shows. Share the link or print the sheet and the numbers travel with it.
Guides for the job in front of you
All guides- Roof Pitch Chart: Angles, Slope and Rafter MultipliersEvery pitch from 1/12 to 24/12 in degrees, percent and rafter multiplier, drawn to scale.
- How Far Apart Are Studs?Why studs sit at 16 or 24 inches, what the code allows and how to find them in a finished wall.
- 2x4 Dimensions and Actual Lumber SizesWhat a 2x4 really measures, with a size chart for boards, framing lumber and posts.
Where the numbers come from.
| Stair risers, treads, nosing, headroom | 2021 IRC, R311.7 |
|---|---|
| Guards on open sides | 2021 IRC, R312.1 |
| Cut stringer throat | AWC DCA 6, deck construction guide |
| Board foot | 144 cubic inches, standard US lumber measure |
| Epoxy volume | 231 cubic inches per US gallon |
This site doesn't publish joist, beam or rafter spans. Those come from American Wood Council tables, and no page here will guess one for you.