# How do you get the board foot of special shapes

How do I calculate the board foot of different shapes other than squares and rectangles? To be more specific, I want to learn to calculate for trapezoids, triangles, cylinders. I dont know much about woodwork so please go easy on term, etc. Thanks!

• You must compute board feet including the scrap. Fit your patterns the best way possible to minimize waste and measure. – Tyson Aug 23 '16 at 1:34
• Hello, and welcome to Stack Exchange. Why do you care? For example, is this to calculate what a mill would charge you, or how much it weighs, or how much buoyancy it would have, or something else? – Daniel Griscom Aug 23 '16 at 1:47

## 1 Answer

Board foot is 12x12x1 inches, so 144 cubic inches, so calculate volume in cubic inches (see your geometery teacher/look up online) and divide by 144.

BUT!

If you want to know "how many board feet I need to buy to make (whatever odd shape of whatever volume)" you'll need to go back to rectangular prisms since lumber is sold in rectangular pieces. And even making rectangular pieces, some waste is expected getting from the rough lumber to the finished product.