Square vs Plumb: What’s the difference?

Technical terms get tossed around all the time in the maker community. And the technical meaning of these terms don’t always translate from country to country, or even different regions within the same country! Two terms we see a lot of confusion on in the maker community is “square” and “plumb”.  Some people use these terms interchangeably, even though they are not. So what is the difference between square vs. plumb?

Square vs Plumb

Understanding the difference between square vs plumb should start with making sure you understand what each of them actually mean.

What does it mean to be square?

Let’s first talk about what it means to be square. And no, we don’t mean to be a an old fashioned person! Your dad my be square, but we’re talking about a different kind of square!

In geometry, a square is a four sided shape (quadrilateral) which means that it has four equal sides and four equal 90 degree angles. A square is also considered a rectangle in which all sides have equal length.

I’m sure you’ve seen squares many times, so then what does it mean to be square when we’re making things? Put as simply as possible when we refer to two lines or faces as square we mean they are perpendicular to each other at a 90 degree angle.

So! Square vs plumb. Let’s move on to plumb!

What does it mean to be plumb?

Plumb is similar to square, in fact they are tied together! Plumb’s definition from Webster’s dictionary simply states “n. Vertical.”  Plumb means that something is square vertically to the ground in all its axis.

The simplest way to understand plumb is to think of a post.  A post can be square to the north/south but leaning to the east west.  If its square in all directions, we would consider it to be plumb!

So! Square vs plumb. Now you know the difference!