I am a cabinet builder at a cabinet company and I want to do a side job for a friend. I have the whole thing drawn up but I donít know how much material to order. There is about 25 running feet of uppers and bases and I am making raised panel doors. I donít know how many board feet of lumber to order. Please let me know if there is an easy way to estimate my material.
From contributor F:
You said you are a cabinet builder - not a cabinet estimator or designer or cabinet layout man or shop owner - just a builder. If that is the case, you havenít needed to know the quantity of your materialls to be a good builder. Someone else figures and orders the wood. And you put it together.
I don't really know an easy way. Since you have it drawn up, now you can tally up all the solid wood in your drawing and do the math to figure the board feet involved. Something good to know: width in inches x length in inches divided by 144 equals board feet. This is also good to know: add thirty percent extra to total net board feet to compensate for waste.
Waste is caused by defects such as knots and also your saw kerfs and most importantly caused by the fact that your parts will not necessarily be neatly, exactly, and evenly extracted from the "random width and length" form that hardwoods are sold in.
These days, rather than calculating the board feet in every piece of wood needed in a particular case I rely on something that only comes with experience. I take an educated guess based on my years of experience. Typically I order in increments of 25 board feet. In other words I round up or down that amount - 150 brd ft, 175 brd ft, 200 brd feet and etc. I do this with common American hardwoods because I know any extra can get used for the next job in that species. With exotics I am much more careful and exacting.
I do know a slight short cut. Measure your cabinet faces - height by length. Multiply the height of the solid wood area by the length of it all in inches. Divide that total by144. That is the total board feet. If your job is euro that is close to your net total discounting - the part of the panel hiding in the groove. If youíre doing face frames add some board feet for the parts where the doors overlap the face frame. Either way donít forget to add 30 percent for waste and mistakes etc.
Anyway, I don't have those features either so here is what I do: for plywood I draw a bunch of rectangles and go through each cabinet figuring up length and width and draw them out on the rectangles representing plywood sheets. This is my cut list and shows me how many sheets of plywood I need. For example you can get four stock size base cabinet sides out of one sheet with some left over for bottoms or shelves.
For doors/ drawer fronts/ face frames I guesstimate and add for waste. Length x width in inches / 144 = bf like others have said. I just calculate the whole cabinet front for example; 12" base cabinet = 12x35/144 = 3bf rounded up and has some waste factor already included. Then add 25 or more bf at the end of all your calculations. This is my method and seems to work out well for me.
Thickness in inches x width in inches x length in feet divided by twelve will give you board feet. Since you are most likely using 4/4 stock for the face frames and doors you can use the formula contributor F gave you but if you go to 5/4 or thicker add the thickness as well.
For face frames I would do pretty much the same thing but not as detailed and would just make sure to order strong until I got to the point I pretty much knew based on the size of the project what it would take for lumber. Now it is much easier with programs like E-Cabinets, which you can download for free, configure to your standard, and get a very accurate cut list in moments.