How to Use a Scale Ruler (For Students) – Architecture and Engineering

How to Use a Scale Ruler

How to use a scale ruler to read and draw architecture and engineering scaled drawings.

If you’re studying architecture, engineering or a similar course, you’ll have to know how to read scale drawings, and draw them yourself – in most cases, using a scale ruler.

Play Video

How to Use a Scale Ruler for architecture and engineering drawings

In my first year of architecture school I was introduced to working in scale. As a refresher, from the “how to read and draw a scale floor plan video”, drawing to scale is drawing an accurate representation of something, usually in a shrunken version of itself.


Scale rulers come in different shapes and sizes, but they all do the same thing.

They come with different scales because you often need to represent things at different scales. For example, a cabinet doesn’t need to be shrunken as much as a whole house would need to be to fit on a page.


The common scales you’ll see on scale rulers are 1:1, 1:5, 1:10, 1:20, 1:50, 1:100, 1:200 and 1:500

Notice how these are all easy numbers to remember. This is really important.


You won’t see any scale rulers or professional architects or engineering drawings at random scales such as 1:7, 1:52 or 1:300.

I see quite a lot of students make their drawings in random scales to fit them on their poster or drawing set. Don’t do that. It makes life difficult.


The reason why these are at the scales they are, is because they are easily divisible. They are easy and fun to work with. The best way to learn how to use a scale ruler is by using one. So, let’s have a look at how we do that.


I’m going to take a stab and say you’ve been given the task to draw a drawing at a certain scale. Let’s say your teacher has asked you to draw a floor plan at a scale of 1:100. – this is quite a typical scale for a floor plan, elevation or section.


So, what does this actually mean? Your teacher wants you to draw your design 100 times smaller than what it would be in real life.


So, drawing a wall that’s 300mm thick, in a 1:100 drawing, would be 100 times smaller than that. 300/100 is 3. So, the 300mm wall would be drawn 3mm wide on paper in a 1:100 drawing.


So, the wall is 3mm wide on paper. Let’s also say it got a length of 7m long. Do you have to divide every single measurement by 100 in order to draw this drawing? The answer is no that would suck if you had to calculate every dimension. In fact, the solution is your scale ruler.


If we navigate to our 1:100 scale, it will actually tell us what 7m would look like on paper.

If you want to draw a 300mm thick wall at 7mm long, all you need to do is follow your scale ruler.


In this video you’ll learn how to use a scale ruler for architecture and engineering.

Resources Mentioned

Further Watching

Other Resources: