About MyShopCalc

Built on the shop floor, not in a software studio

MyShopCalc grew out of a custom cabinet shop. Every number here is one we reached for while laying out a real run of cabinetry — setting a 34-1/2"876 mmbase carcass over a 4" toe kick, splitting a shared stile between a pair of five-piece Shaker doors, or sizing an undermount drawer box to clear the slide mechanism. After years of re-deriving overlays on the back of a cut list and rebuilding the same spreadsheet formulas, we built the calculators we actually wanted at the bench.

That background shapes what the tools assume. They speak the trade's language: the 32 mm system's line-boring increments, full-overlay and compact overlay geometry, the cup boring distances printed in Blum and Salice hinge catalogs, and the drawer-box clearances that make an undermount slide run true instead of binding.

Why these tools exist

Shop math is not hard — it is just relentless. A door overlay gets recalculated a dozen times a day, and one missed reveal means a refit. The alternatives we had were either a sprawling spreadsheet that broke the moment a project changed, or a full design suite that assumed a desk and a mouse instead of a tablesaw and a pencil. Neither belongs on the shop floor.

MyShopCalc replaces both with instant answers. Each calculator runs entirely in your browser: type a dimension, read the result, and get back to work. Nothing you enter is uploaded, there are no accounts, and the pages load fast enough to use with sawdust on your hands. The math is fast, private, and free.

What the math is built on

The formulas come directly from accepted trade practice and published hardware data, not from guesswork. A few of the constants that anchor the calculators:

A 35 mm concealed hinge cup is bored to the edge distance and boring distance in the manufacturer's datasheet (1-3/8"–1-1/2"34–37 mm covers most full-overlay hinges); a Tandem undermount slide expects a drawer box whose outside depth matches the nominal slide length; and stair stringers are laid out to the IRC maximum riser of7-3/4"197 mm and minimum tread of 10"254 mm. Where a governing standard applies, we follow it.

Editorial & accuracy standards

• ▪Shop tolerances, not rounded-off guesses. Results render as exact decimals and as clean fractional cut sizes to the nearest 1/16" and 1/32"millimeter — the increments you can actually mark and cut to.
• ▪Sourced from standards and datasheets. Riser and tread limits follow the IRC; hinge and slide clearances follow the hardware maker's published specifications.
• ▪Show the work. Every calculator page includes a "The Math Behind…" section and a FAQ so you can see how a result is derived and check it against your own job.
• ▪Estimates, verified at the bench. Calculators are a starting point — always confirm final dimensions against the actual opening and dry-fit before cutting.

Get in touch

Have a calculator you want built, a correction to the math, or a question about a standard we cite? Write to us — we read every message athello@myshopcalc.com.