What Is Scale in AutoCAD? Types, Uses & How to Set It

 

What is scale in AutoCAD drawing? If you're new to learning AutoCAD, you'll likely be confused by the idea of drawing scale. From creating architectural floor plans and mechanical components to site plans and engineering drawings, knowing what scale to use in AutoCAD ensures that your designs communicate the right information regarding size.

So, what is scale in AutoCAD drawing? Let's briefly define the term: scale is the ratio of a drawn object's size relative to the actual object's size. With AutoCAD, you can create full-size objects and control their display in model space or when printing to paper.

The scale becomes important when you're getting ready to print or plot your drawing, add layout and viewport scales, create presentation drawings, and so on. In this article, we'll walk you through the scale in AutoCAD and explain how to use it.

What Is Scale in AutoCAD Drawing?

Now that you know what to do when you don't know what scale to use in AutoCAD, let's define the scale in AutoCAD drawing. Imagine that you need to draw a building that is 20 meters long. One option is to draw the model using its actual dimensions in AutoCAD rather than reducing it on your sheet.

It is best practice to draw the model at 1:1 scale (or full scale) in AutoCAD most of the time. Then you can use a scale to control how large or small something is displayed or plotted in paper space.

For instance, if you were working in millimeters and you had a 5,000 mm wall, you would draw a 5,000 mm long segment instead of reducing it to, say, 500 mm.

Then, you change the scale, depending on what you need:

• 1:1 - 1 Unit in the drawing equals 1 unit on paper (full scale).

• 1:2 - 1 Unit in the drawing equals 2 units on paper (half scale).

• 1:10 - 1 Unit on paper equals 10 units in the model.

• 1:50 - Commonly used architectural scale for floor plans.

• 1:100 - Architectural scale for larger buildings and sites.

So, you could keep objects at full scale and make the necessary changes when you need to display them at a particular scale in paper space.

Why Is Scale Important in AutoCAD?

Knowing what scale to use in AutoCAD is important, as scale has an essential impact on the way your drawings are visualized or perceived. For instance, you might not want to print a large-scale architectural floor plan because it'll take too much space on your paper. However, you might want to print another architectural drawing at a smaller scale because it'd still have enough detail to be useful.

The scale can also help you maintain the accuracy of the design elements, produce construction documents at a readable size, display different levels of detail in a set of construction drawings, and so on.

Without the correct scale, it'd be quite challenging to produce documents that would clearly communicate your ideas. By applying the appropriate scale, you'd be able to ensure that drawings are both accurate and simple to read. You can also apply a specific scale ratio to control the amount of detail that's needed in a particular drawing or a specific viewport.

How Does AutoCAD Drawing Scale Work?

One of the first questions that arise when you're trying to learn what scale to use in AutoCAD is: should I draw my objects at scale or full size? And what's the difference between model space and paper space?

In most cases, you want to avoid scaling your drawing. Instead, you can work with objects in model space at a 1:1 scale. Model space is where you create the bulk of your design. So, if you need to draw a rectangular room that is 4 by 5 meters, you'll set the width to 4000 mm and the length to 5000 mm (if you're working in millimeters).

You don't need to reduce the drawing to 80 by 100 mm simply because you're going to need to print that on paper. Once you've completed the model, you can use layouts to create viewport scales to control how much of the model will be visible in each viewport.

Note: Using AutoCAD layout viewports is one of the most common ways that people display a full-size model in paper space at different scales.

Common AutoCAD Drawing Scales

There's no specific scale that you will use for every drawing in AutoCAD. The scale should be chosen based on how big the object is and what level of detail you need to convey in your drawing. Below are some of the most commonly used drawing scales:

1:1 Scale

1:1 Scale is a life-size scale that you can use for small components, details, and objects that can fit on a selected paper size.

1:10 Scale

1:10 Scale is a good choice for many components or detail drawings because it reduces the size of the drawing by a significant amount while maintaining enough detail.

1:20 Scale

1:20 Scale is a good option for many architectural details and drawings of internal elements or fittings.

1:50 Scale

1:50 is a commonly used architectural scale for many types of drawings, including floor plans and sections.

1:100 Scale

1:100 Architectural scale is often used for larger buildings and construction drawings and is commonly used for site plans.

1:200 And Smaller Scales

Larger sites, master planning, and city plans may use scales such as 1:200, 1:500, or 1:1000.

How to Set Scale in an AutoCAD Layout

Now that we've covered what scale to use in AutoCAD, let's look at how to set the scale in an AutoCAD layout. The following are the basic steps for setting the scale in an AutoCAD layout view:

Step 1: Create Your Model

Draw your model using real-world units.

Step 2: Open a Layout

Go to a layout tab and then create a paper space viewport. Make sure that the sheet is the right size. Choose any paper size (A4, A3, A2, A1, etc.).

Step 3: Create a Viewport

Create a viewport that displays your model. You'll want to make sure that the drawing occupies the entire layout.

Step 4: Select the Viewport Scale

Select the viewport and set the scale that you want to use. If you need to set the architectural scale, make sure to set it to 1:50 or 1:100 for a floor plan.

Step 5: Lock the Viewport

Once you've set the scale, make sure to lock the viewport so that it isn't changed accidentally.

Step 6: Check the Drawing

Double-check everything before you plot your drawing. Make sure that the line widths, text sizes, dimensions, lineweights, and sheet appearance are correct.

Understanding Annotation Scale

The AutoCAD annotation scale is a term that we haven't mentioned, as we've looked at some of the basic principles of working with scale in AutoCAD. Annotations typically include dimensions, text, leaders, hatches, multileaders, blocks, or symbols.

When working with multiple viewports that have different scales, annotations such as text and dimensions must appear the same way in all viewports. This means that text, dimension sizes, and hatch patterns must also be adjusted when changing scales. It can get a bit complicated, but AutoCAD has some built-in tools that can help with annotation scaling.

Annotation scales can be a great way to make your drawings more readable and help keep your text and dimensions more consistent across multiple viewports. We recommend that you use annotative objects when it comes to dimensions, text, and other annotations.

Model Space Scale vs Paper Space Scale

One of the most common mistakes that beginners make is to confuse model space and paper space in AutoCAD. When it comes to model space, most of your drawing should be done at a 1:1 scale.

When it comes to paper space, most of your time should be spent in paper space, adding titles, notes, and other information, and inserting viewports. Viewports are like windows into your model space, and each one of them can have its own scale.

The easiest way to think about this is that model space represents the real world. Paper space, on the other hand, is where you create presentation drawings for your clients.

How to Calculate AutoCAD Scale

In some cases, you might need to manually calculate a scale in AutoCAD. The formula in this case is pretty straightforward: drawing scale equals the drawing size divided by the actual size. So you might want to do something like the following when calculating scale in AutoCAD:

Suppose that you have a 5-meter wall that you want to represent in a 100 mm scale. First, you need to convert meters into millimeters: 5 meters equals 5000 mm. Then, you calculate the scale by dividing 100 mm by 5000 mm:

100 ÷ 5,000 = 1/50

Common Scale Mistakes in AutoCAD

At this point, we've hopefully covered the basics of what scale to use in AutoCAD. The next step is to take a closer look at some of the most common mistakes that people tend to make when it comes to working with scale in AutoCAD.

Scaling the Model Instead of the Viewport

It's a common beginner mistake to scale the entire model in model space rather than using a viewport scale in paper space. The problem with this approach is that it can lead to confusion down the line.

You should avoid scaling your model in model space. Rather than doing that, adjust the viewport scale so that your model fits better on the page.

Forgetting to Lock Viewports

When working with viewports and different scales, it's easy to forget to lock a viewport after you've set the scale. As a result, any changes that you make with the zoom tool will change the scale of the viewport. To prevent this from happening, always remember to lock a viewport after you've set the scale.

Using Incorrect Drawing Units

Working with the wrong units in drawing can lead to serious problems. For instance, you might be working on a drawing that's supposed to use millimeters, but some of your model elements were created using inches. This mistake could affect the accuracy of your dimensions when it comes to printing or when you need to combine two drawings.

Always make sure that you're using the correct units. Set the drawing units before you start working on a new drawing or project.

Ignoring Annotation Scale

While it's important to pay attention to the geometry of your drawing, it's equally important to make sure that all of your annotations are easily readable. When working with multiple viewports, you might end up adjusting the text size so it looks good at one scale, only to find out later that it might be almost invisible at another scale.

Always make sure that annotations are set to use a scale that you'll be using when it comes to plotting or printing your drawing.

Not Checking the Printed Output

If you're working with scale in AutoCAD, you might want to double-check what the final printed output will look like before you send it to a plotter or printer. The easiest way to do that is to preview your drawing and make sure that everything looks good. Double-check any dimensions that you feel are important. It's always a good idea to use a test sheet or use another known measurement to make sure that your drawing is correctly plotted.

Tips for Using Scale Professionally

Here are a few additional tips that you can use when it comes to working with scale in AutoCAD:

- When possible, draw objects at their real-world dimensions.

- Always choose your units before you begin working on a new drawing.

- Use layouts and viewports to create presentation drawings.

- Choose an appropriate scale based on the requirements of your drawing.

- Once you've set the scale, remember to lock a viewport so that it doesn't change.

- When working with multiple viewports, use annotative objects.

- Make sure that your lineweights and text size are appropriate for the print size.

- Always preview your drawing before you print it.

- When creating any presentation drawings, make sure that you use a standard title block and indicate the scale.

- When creating presentation drawings, use a graphic scale bar where applicable.

By using these tips, you'll be able to avoid any common scale errors and make sure that your drawings are easier to read and understand no matter who decides to open them.

Why AutoCAD Scale Can Be Confusing to Beginners

As you can see, there is quite a lot to consider when it comes to learning what scale to use in AutoCAD. The main issue that most beginners face when it comes to scale is the fact that model space drawing scale isn't necessarily related to the actual paper drawing scale.

When working with manual drawing or drafting, we might decide to use a scale of 1:50 for a building plan or a section drawing. Using AutoCAD, we could simply draw the actual building and then decide how we want to display it using a scale in a layout.

By using AutoCAD, we can ensure that our building model is accurate no matter which viewport scale we decide to use. For instance, we could show the same building in several different scales:

• 1:100 Scale drawing (building floor plan).

• 1:50 Scale drawing (building floor plan, enlarged).

• 1:20 Scale drawing (building construction details).

• 1:10 Scale drawing (building interior details).

This means that we won't have to spend hours creating four different building drawings when we only need to create a few variations of the same building model. Instead, we can use different viewports and scales to ensure that all of our construction documents look good and are easy to read.

Final Thoughts

What is scale in AutoCAD drawing? At this point, we've hopefully covered the basics of what scale to use in AutoCAD. We've explained that scale refers to the ratio of a drawn object's size relative to the actual object's size. We've also gone over the basics of model and paper space, explained how to set scale in AutoCAD, and given you some tips for working with scale in AutoCAD.

Now that you know more about what scale to use in AutoCAD, you'll be able to create presentation drawings, architectural drawings, mechanical drawings, and construction drawings at the right scale. We'll also give you the answers to some of the most frequently asked questions regarding scale and AutoCAD.

Frequently Asked Questions

1. What is the best scale for an AutoCAD drawing?

There is no "best" scale for AutoCAD drawings. It all depends on the type of drawing, the paper size, the size of the object, and the level of detail. Architectural scale drawings usually use the scale of 1:50 or 1:100. Mechanical scale drawings often use scales such as 1:10 or 1:20.

2. Should I draw at scale in AutoCAD Model Space?

You should generally draw objects at their actual size in model space. Then, you can use a scale to control how large or small something is displayed or printed out. By using AutoCAD model space and paper space, you can control how large or small an object will be displayed at scale.