How to Set the Annotation Scale in AutoCAD

The annotation scale determines how large texts and symbols appear on paper, regardless of the drawing scale.

An annotative object is an object that you set to the desired paper size, after which AutoCAD automatically displays it at the correct model size for each annotation scale. You draw a building at actual size, but text must be, for example, 2.5 mm high on paper, whether you plot that drawing at 1:50 or 1:100.

Previously you calculated the text height manually: 2.5 mm at a scale of 1:100 meant 250 mm in the model. A different height for each scale, and when the scale changed everything had to be redone. With annotative objects you set the paper size once and let AutoCAD handle the rest. This works for text, dimensions, multileaders, hatches, and blocks.

The calculation behind the scenes is simple: model size = paper size × scale factor. So at 1:50, 2.5 mm becomes 125 mm; at 1:100, it becomes 250 mm. The benefit of working annotatively is that you never have to make that calculation yourself, and one object can display both values at the same time, each in its corresponding viewport. Objects that are not annotative keep their fixed model size and appear the same size relative to the drawing at every scale – exactly what you want to avoid with annotations.

You make an object annotative by setting the style or the object itself to annotative.

Annotative behaviour starts with the style. This is how you set the most commonly used objects to annotative:

• Text: open the Text Style (STYLE), tick Annotative and enter the desired paper text height under Paper Text Height, for example 2.5 mm.
• Dimensions: open the Dimension Style (DIMSTYLE), Fit tab, and turn on Annotative under Scale for dimension features.
• Multileaders: in the Multileader Style (MLEADERSTYLE) turn on Annotative on the Leader Structure tab.
• Hatches: in the Hatch dialog box tick Annotative so the pattern stays at paper scale.
• Blocks: in the Block Definition (BLOCK) tick Annotative when creating the block.

You can also make an existing object annotative: select it, open the Properties palette (Ctrl+1) and set Annotative to Yes. You can recognise an annotative object by an icon: a small triangular scale symbol appears next to the cursor when you hover over it.

Mix annotative and non-annotative objects thoughtfully. A title block and border lines are usually not annotative, because they sit at actual paper size in the layout. Text, dimensions and symbols in the model, on the other hand, should be annotative. Keep that separation and your drawing stays predictable at every scale change.

The current annotation scale is set on the status bar or with CANNOSCALE.

At the bottom-right of the status bar you’ll find the Annotation Scale. Click it and choose the scale you are working at, for example 1:100. This value is the system variable CANNOSCALE; you can also set it via the command line.

Command: CANNOSCALE
New value for CANNOSCALE: 1:100

If the scale you need (such as 1:50) is not in the list, add it with SCALELISTEDIT. Click Add, give it a name and the ratio between paper and drawing units. Remove superfluous scales in the same window to keep the list tidy.

Always set the annotation scale correctly before placing annotations. Text you type at scale 1:100 automatically gets the associated model size; if you later switch to 1:50, the text stays the same size on paper.

The scale list works with metric or imperial units, depending on your template. For Dutch construction work you use metric scales such as 1:5, 1:10, 1:20, 1:50 and 1:100. If they are missing, you are probably in an imperial template; start a new drawing from a metric template (for example acadiso.dwt) or add the scales manually. This prevents text heights from looking odd because the units don’t match.

One annotative object can display multiple scales via scale representations.

The power of annotative objects is that a single object stores multiple scale representations. This way you can show the same text correctly in a detail at 1:20 and in an overview at 1:100, without duplicating.

There are two ways to add an extra scale to an object:

1. Automatically: turn on the Automatically add scales button (system variable ANNOAUTOSCALE, the lightning-bolt icon next to the annotation scale on the status bar). Every time you change the annotation scale, existing annotative objects gain that new scale.
2. Manually: select the objects and use OBJECTSCALE. In the Annotative Object Scale window you can add or remove scales. This gives you precise control over which scales an object shows.

A handy check: turn on SELECTIONANNODISPLAY; then when you select an annotative object, each scale representation lights up in light grey. You can see at a glance which scales are attached to the object and whether a representation has been moved far from the rest.

If you move text in one scale level, you can set the position per representation independently. So a label can sit slightly differently in the detail than in the overview, while remaining one object. Be careful with ANNOAUTOSCALE: if it is on while you browse through many scales, objects quickly accumulate scales you don’t need. Clean those up with OBJECTSCALE to keep the file light.

In a layout AutoCAD links the viewport scale to the annotation scale.

The real work happens in a layout (paper space). When you select a viewport and set the viewport scale, the annotation scale adopts that value as long as synchronisation is enabled. A viewport at 1:100 then shows only the annotation representations that exist for 1:100.

You work practically like this:

1. Create a viewport in the layout and set the scale (for example 1:100).
2. Lock the viewport (PSPACE, then the lock icon on the status bar) so the scale doesn’t accidentally shift.
3. Check that the text is at the desired paper size.

To show the same text in two viewports with different scales, make sure the object has both scale representations. If a representation is missing, the text will not appear in that viewport, unless you force the display with ANNOALLVISIBLE. This method ties in with how you export a DWG to PDF: the plot follows exactly what the viewport shows at scale.

If you work in model space itself, the annotation scale on the status bar directly determines what you see. Set it there to the scale of the layout the drawing will eventually go into, so the text already has the correct size while you draw. Two viewports with different scales on one layout is very common: a floor plan at 1:100 alongside an enlarged detail at 1:20, where the same annotative labels sit neatly at paper size in both.

Choose a fixed paper height for text, such as 2.5 or 3.5 mm.

Consistent text starts with a fixed set of paper heights. In construction and building services these often follow the standardised series. Choose a height per function and stick to it in all your styles:

Set these heights in your text styles and your template (.dwt). Then for each drawing you only need to choose the annotation scale and the text height on paper automatically works. Combine this with a cleaned-up scale list via SCALELISTEDIT so you only see the scales you actually use.

These commands and system variables control the annotation scale.

Missing or duplicated annotations are resolved with ANNOALLVISIBLE, ANNOUPDATE and ANNORESET.

A few situations often occur:

• Text disappears when you change the scale: the object has no representation for that scale. Add the scale with OBJECTSCALE, or temporarily turn on ANNOALLVISIBLE to see what is still there.
• Duplicate or offset text: representations have been moved separately. Use ANNORESET to return them to the position of the current scale.
• Object does not follow the new scale: run ANNOUPDATE on the selection to update it to the active annotation scale.
• Text plots at the wrong size: check whether the object is truly annotative (Properties) and whether the paper height is correct in the text style.

If you take your workflow to another computer, your templates (.dwt) with the pre-set scale list and styles travel with you; see transferring an Autodesk licence to a new PC for the installation side. Those who also work with Revit will recognise the principle: annotations scale there with the view scale, which reappears when you create a Revit family with its own labels. More detail can be found in the Autodesk documentation on annotative objects and annotation scaling.