Charts
- Fraction to decimal chart for inches, with millimeters and feetA fraction to decimal chart for every 64th of an inch, with millimeters and decimal feet, plus inches to decimal feet. Free printable PDF, US Letter.
- Roof pitch chart: 1/12 to 24/12 in degrees, slope and rafter lengthA roof pitch chart from 1/12 to 24/12: the angle in degrees, slope percent, plumb and seat cuts, and rafter length per foot of run. Free printable PDF.
- Stair rise and run code: IRC 2021 limits with worked layoutsThe 2021 IRC limits for stair risers (7-3/4" max) and treads (10" min), the 7-11 rule, and worked stair layouts for rises from 2' to 10'. Free PDF.
- What is a board foot, and how to calculate board feetA board foot is 144 cubic inches of lumber, 12" × 12" × 1". How to calculate board feet from nominal sizes, with a printable chart for 1x4 to 6x6.
- How many bags of concrete in a yard: 80, 60 and 40 lb bagsAbout 45 bags of 80 lb concrete make a cubic yard, 60 of 60 lb, 90 of 40 lb. A slab chart in yards and bags with 10% waste, as a free printable PDF.
- How to calculate square footage from inches and fractionsMultiply length × width in inches and divide by 144 for square feet. Worked examples with feet, inches and fractions, done exactly, and a printable chart.
- Crown molding angles chart for cutting crown flat on a miter sawMiter and bevel settings for 52/38 and 45/45 crown molding cut flat on a compound miter saw, for wall corners from 60° to 150°. Free printable chart.
How the charts are made
Each chart is worked out with the same steps as Construction Calculator 1.1.1, the version on the App Store: exact fractions of an inch, lengths rounded to the nearest 1/16" only at the end (marked ≈ when rounded), angles to a tenth of a degree. Those steps are checked against the app’s own tests, and the site is not published if any number on a chart page or in its PDF differs from what they give.
Codes and suppliers
The stair and roof pages cite the 2021 International Residential Code by section, and say where the 2024 edition renumbers a section (its limits are the same). Those pages sum up the model code and are not legal advice: your local code may be a different edition or amended, so check it before you build. Bag yields and lumber tallies vary by brand and supplier; the concrete and board feet pages say where.