About Workshop Calculators

I have spent most of my life building, repairing, designing, and trying to solve problems that did not come with useful instructions. This site is where I am putting the calculators and references I wish I had when I needed them.

Why I built this

I am a systemizer. I tend to see the relationships underneath a problem, which is useful right up until I have to explain why the answer makes sense to someone who is looking at it from another direction. That is why these calculators do more than return a number. They explain the measurement, show the formula, and name the conditions the math cannot see.

I built custom guitars professionally, worked as a contractor, made furniture, repaired equipment, built exhibits, dealt with electronics, and spent years teaching people how the pieces fit together. The tools here come from the same kind of work.

How I check the math

Every calculator should survive a hand calculated example, a second independent example, fractions, decimals, metric values, empty fields, impossible values, and the places where rounding changes the answer. The worked example on the page needs to match the code. Typing a separate example and hoping it agrees is not testing.

What the calculator cannot see

A correct calculation does not prove the project is safe. The site cannot see cracked material, poor installation, side loading, impact, vibration, heat, moisture, corrosion, manufacturing tolerances, or a measurement taken from the wrong place. The math is one part of the job.

Gelvin Guitars

I also created Gelvin Guitars. Some of these tools are useful for guitar building, repair, electronics and layout, so the sites will link to each other where the connection makes sense.

About Goldie

Marigold, usually called Goldie, is the fictional search assistant and workshop guide used throughout this site. Her personality was shaped by traits shared by several assistants I have worked with over the years, but she is not intended to represent any one person. Her appearance, name and role were created for this character.

Found a problem?

I check these calculators before publishing them, but I am capable of making a mistake. If you find a result that does not look right, send me the inputs you used and what you expected to happen. I would rather fix the calculator than defend an error.