Learning to Scale an AutoCAD

A visual representation of something larger at a smaller scale is immensely helpful in a myriad of tasks. An AutoCAD 3D drawing, or even an AutoCAD 2D Drawing, can provide that representation with computerised scaling for greater accuracy. Scaling can impact how the actual thing is installed and built, and whether it is up to code in this process. Improper scaling in AutoCAD drawings can lead to miscommunication and other unwanted results. It is crucial to scale objects accurately in the AutoCAD drawing viewer, especially since the actual building or construction will require that design.

Using the Scale Command in AutoCAD Drawing Viewer

The first thing to do in using the SCALE command in AutoCAD is the find an object in the drawing at 1:1 scale or a line whose length you already know. Type in SC, or SCALE for the scaling command, and then select the object or objects that you want to scale to a specific size. Specify a number between 0 and 1, and hit the RETURN or ENTER key. This value – if it is lower than 1 – will scale down the selected object by the scale factor set. If you want to scale an item up from its original size, a number higher than one (1) will have to be selected.

Scaling External References in an AutoCAD Drawing

When it comes to using AutoCAD, reference files such as PDFs, drawing files, and images are already provided by other CAD designers which can be used as a basis in AutoCAD. You can insert these items into your AutoCAD drawing viewer through the XRED window, but their scaling is not guaranteed to be true to size. An image in the background can have a certain distance, but the dimension size can differ if that image is inserted into your drawing. In these events, the ALIGN command will come in handy, as it allows for confirmation of the dimensions of external reference objects inserted in a drawing.

In this case, the best thing to do is to first look for a dimension that can be taken for reference. For example, if the objects you are inserting already have their sizes mentioned, then using those values is the next best thing. Suppose there is no point of reference already, then you can make one by assuming a dimensional number. These allow for accuracy and consistency in the drawing. The next step is to draw a line as per the external reference and its dimensions. For example, if the measurements of a wall are assumed to be 10ft height, then drawing a line in your AutoCAD 3D drawing to fit that model space can help you check if your assumed reference dimension fits. After that, the next step is to use the ALIGN commands and match the start and endpoints. Once that is done, Hit the ENTER or RETURN key to have your CAD insertion scale to fit your AutoCAD 3D drawing. You can repeat these steps if their consistency has to be checked with various dimensions, and verifying can save you from a headache further down the line.

Scaling Blocks in AutoCAD

In AutoCAD, a block is one named object which contains a collection of objects that are not named. If you use AutoCAD blocks frequently or are only looking for a guide for their scaling and variation, then here is how you can scale blocks in AutoCAD. For inserting a block, type INSERT, and a prompt will open up. It will contain options for scale, rotation, and more. If blocks are not made to a uniform scale, you can specify them on the three-dimensional scale across the X, Y, and Z dimensions.

Scale Text and Dimensions in AutoCAD

Having readable texts in your drawing is critical, regardless of the scale you are plotting the drawing. To quickly solve the text-to-scale problem, AutoCAD introduced annotations and the annotative scale, which allows for a uniform size at any given scale. While this feature has been around for more than a decade, there are still various issues or potential problems you have to consider. The most immediate among them is that your text and the annotation object scale do not conflict, which can make the text disappear in certain instances, but perfectly functional in others. To solve this, set the text and dimensions to ‘annotative’ in its properties. This feature allows for automatic adjustment to scale as you introduce new instances or edit your drawing, regardless of the type of scale you use.

Scale a Drawing in AutoCAD

Your objects are now scaled, but your drawing still needs to be fitted on a piece of paper for better visual representation. Before that, however, a drawing scale has to be set. AutoCAD provides drawing scales in a list of options, but you can set custom values for it as well if the included objects are not what you need. To determine a custom drawing scale, go to the ‘Edit Drawing Scales’ window and select the Custom option in the list of scales. This custom value can allow you to use your preferred scale to be viewed in the AutoCAD viewport.

Plot to Scale in AutoCAD

Making an AutoCAD drawing in a model space allows you to make it to the full size, but it has to be portrayed in a deliverable. After the drawing scale is set, it has to be plotted, which allows you to display your CAD design to your selected paper accurately. There are two scales when plotting for a miniature model. The first is the paper to which the drawing is scaled to, based on a 1:1 scale ratio. The other is the AutoCAD viewport which shows the model size. One option to plot to scale is to use the model space, which uses the model space plot scale as the ratio of the units’ real-world size.


AutoCAD has several areas where its scaling features come into play, and allow you to make the most accurate and authentic AutoCAD drawing to the real-world object it is supposed to be representing. As that design can be used to determine if the project is worthwhile, any inaccuracies or miscalculations can cause some problems. However, with this guide, you can mitigate that possibility altogether.

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