As much as I do enjoy coming up with my own designs and projects, building them in my mind, working through the specifics of design, I also look at a LOT of woodworking plans.
I’ve gotten to the point that I don’t necessarily care whether the plan is in imperial or metric, but I do know a lot of people who are only comfortable working with plans that use the same measurement scale that is ‘native’ to their country, and as such pass up on the opportunity to use some incredible designs just because they are drawn up in inches and not millimetres (or the reverse).
At times, it really does become necessary to work in one, or the other, or worse, mix the two in the same project. In Australia for example, being metric and mm being our forte, we run into a constant problem that often not only are the plans in imperial, but so are the tools! Router bits are imperial, that is just a fact. Often the same with other cutters, such as dado blades etc. So what do we do? Abandon projects that require a conversion? Constantly get out a calculator and divide the fraction then multiply by 25.4? Or just use a better calculator.
The FastCap Converter Pro, from Professional Woodworkers Supplies allows calculations in digital imperial, fraction, and metric all in the same calculation and then have the answer in metric or a fraction (and flick between the two).
So if you wanted to add 2.52″ + 2 5/32 +37.5mm you can. Easily.
(The answer is 6 1/8″ or 156.28mm fwiw (and yes, I’d just round it to 156!)
Or subtract the kerf of your blade, measured using a digital caliper. Or whatever.
The point is, you don’t have to ignore projects, plans, tools that use a measuring system you are not confident with. And that is the advantage that having the Converter Pro in your pocket gives you.