Sawdust Sessions

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Free tools

Woodworking and lumber calculators

Four free tools for the arithmetic between reading a plan and getting to the timber yard. No sign up, nothing to install, and they all account for the blade kerf, which is where most hand calculations go wrong.

Which one do you need?

If you are buying hardwood by the board foot, start with the board foot calculator. That is how lumber yards price anything an inch thick or more, and it is a volume rather than a length, which catches people out.

If you are buying construction lumber such as 2x4s, the cut list calculator is more useful. Those are sold by the piece, so the question is how many boards you need and how to get all your parts out of them.

If you are working in sheet goods, use the plywood cut calculator. Laying parts out on a 4 by 8 sheet is a different problem to cutting lengths off a board, and grain direction limits how much you can rotate things to save material.

And before you carry any of it, the lumber weight calculator will tell you what you are actually lifting. A sheet of three quarter inch MDF is close to a hundred pounds.

They all account for the kerf

Every cut removes a slice of material the width of the blade, usually about an eighth of an inch. Across a dozen cuts that is well over an inch of timber gone to sawdust. Plans and hand calculations routinely ignore it, which is why people get to the last part and find the board is short. Our guides on measuring and marking and reading woodworking plans cover the same ground for the parts you do by hand.

See the 16,000 plans

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