AutoCAD Dimension & Text Styles for Civil Drawings: Setup, Scales & Standards (2026)

You drew everything perfectly. Every line snapped, every wall is exactly 230 mm. Then you added dimensions with the default AutoCAD dimension style, and the numbers came out so tiny you need to zoom in 50 times to read them. Or the arrows are the size of a car.

This is the most common problem beginners face in AutoCAD, and it has nothing to do with drawing skill. It happens because the dimension style and text style were never set up for the drawing scale.

This is Lesson 3 of our free AutoCAD for Civil Engineers series. By the end you will have one set of text and dimension styles that print correctly at 1:50, 1:100 and 1:500, every time.

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Why Dimensions and Text Matter More Than You Think

A civil drawing is a legal and technical document. The contractor on site does not measure your lines. They read your numbers.

• A dimension that reads 3649 instead of 3650 makes the site engineer doubt the whole drawing.
• Text that is 1 mm tall on paper cannot be read in a dusty site office.
• Mixed fonts and sizes make a drawing look like it was made by five different people.

Clients, consultants and examiners judge your drawing in the first five seconds, and annotation is what they see first.

The One Idea That Fixes Everything: Paper Height × Scale

You draw in model space at full size. A 3 m wall is 3000 units long. But your text must be readable on paper, where a normal note is 2.5 mm tall.

So if you will print at 1:100, the text in model space must be 100 times bigger:

Model text height = Paper text height × Scale factor
2.5 mm × 100 = 250 units

That is the whole secret. AutoCAD gives you a setting that does this multiplication for you: DIMSCALE (called “Use overall scale of” in the dimension style dialog).

Text Height Chart for Every Common Scale

Standard lettering sizes from SP 46 (Engineering Drawing Practice) and ISO 3098 are 2.5, 3.5, 5, 7 and 10 mm. Here is what they become in model space (drawing units = mm):

Which Height for What?

Do not use more than three or four sizes in one drawing. Consistency looks professional.

Part 1: Create a Text Style (STYLE)

A text style decides the font, width and height of your text.

1. Type ST and press Enter. The Text Style dialog opens.
2. Click New and name it TCS-TEXT.
3. Font name: choose Arial (clean and universal) or romans.shx (the classic CAD look, very light files).
4. Height: leave it at 0.
5. Width factor: 1.0 (use 0.8 if your schedules are crowded).
6. Click Apply, then Set Current.
7. Repeat to create TCS-DIM with the same settings. This one will be used only by dimensions.

SHX or TrueType?

For student work and client submissions, Arial is the safer choice.

Part 2: Create an AutoCAD Dimension Style (DIMSTYLE)

Your AutoCAD dimension style controls every arrow, gap and number. Type D and press Enter to open the Dimension Style Manager. Click New, start from ISO-25, and name the new style TCS-100 (for 1:100 drawings).

Now go through the tabs. These are the settings we recommend for civil and building drawings.

Lines Tab

Symbols and Arrows Tab

Text Tab

Fit Tab (the important one)

Under Scale for dimension features, select Use overall scale of and type 100.

This single number multiplies every size on the other tabs: 2.5 mm text becomes 250 units, 2 mm ticks become 200 units. That is exactly what a 1:100 print needs.

Also tick “Place text manually” off and keep “Always draw dim line between ext lines” on.

Primary Units Tab

Click OK, then Set Current. You now have a working 1:100 dimension style.

Make One Style Per Scale

Copy TCS-100 and change only the overall scale:

Show Metres on Site Plans (Without Redrawing)

Site plans and road drawings usually show metres (12.500), but you still draw in mm. In the TCS-SITE-500 style:

• Primary Units → Measurement scale factor: 0.001
• Precision: 0.000
• Zero suppression: untick Trailing so 3.650 does not turn into 3.65

A line 12500 units long now reads 12.500. You never touched the geometry.

Part 3: Put Annotation on the Right Layer

From Lesson 1, you already have:

• G-DIMS for all dimensions
• G-TEXT for all notes and labels

Make G-DIMS current before you dimension, and G-TEXT before you write notes. Now you can freeze all dimensions with one click when you need a clean plan for presentation.

The Dimension Commands You Will Actually Use

The Professional Way to Dimension a Floor Plan

Real drawings use three strings of dimensions on each side:

1. Inner string: walls and openings (doors, windows). Use DLI for the first, then DCO for the rest.
2. Middle string: grid line to grid line (column centres).
3. Outer string: overall building length.

Then run DIMSPACE, pick the inner string as the base, select the other two, and type 8 × scale (for 1:100 that is 800) or press Enter for Auto.

Text Commands: TEXT vs MTEXT

Special Characters Every Civil Engineer Needs

Type these codes in TEXT, MTEXT or in a dimension override:

Bonus: Create All Styles in One Command (AutoLISP)

Like the SNAPSET routine in Lesson 2, this LISP creates both text styles and all three dimension styles in a second. Paste it into Notepad, save it as TCSDIM.lsp, load it with APPLOAD, then type TCSDIM.

;; TCSDIM - TheCivilStudies text + dimension styles (drawing units = mm)
(defun tcs:mkstyle (name font)
  (if (not (tblsearch "STYLE" name))
    (entmake (list '(0 . "STYLE")
                   '(100 . "AcDbSymbolTableRecord")
                   '(100 . "AcDbTextStyleTableRecord")
                   (cons 2 name) '(70 . 0) '(40 . 0.0) '(41 . 1.0)
                   '(50 . 0.0) '(71 . 0) '(42 . 2.5)
                   (cons 3 font) '(4 . "")))))

(defun tcs:mkdim (name sc lfac dec)
  (setvar "DIMTXSTY" "TCS-DIM")
  (setvar "DIMSCALE" sc)
  (setvar "DIMTXT" 2.5)
  (setvar "DIMASZ" 2.0)
  (setvar "DIMBLK" "_ARCHTICK")
  (setvar "DIMEXE" 2.0)
  (setvar "DIMEXO" 2.0)
  (setvar "DIMGAP" 1.0)
  (setvar "DIMDLI" 8.0)
  (setvar "DIMTAD" 1)
  (setvar "DIMTIH" 0)
  (setvar "DIMTOH" 0)
  (setvar "DIMLUNIT" 2)
  (setvar "DIMDEC" dec)
  (setvar "DIMZIN" 0)
  (setvar "DIMDSEP" ".")
  (setvar "DIMLFAC" lfac)
  (if (tblsearch "DIMSTYLE" name)
    (command "_.-DIMSTYLE" "_S" name "_Y")
    (command "_.-DIMSTYLE" "_S" name)))

(defun c:TCSDIM (/ oldecho)
  (setq oldecho (getvar "CMDECHO"))
  (setvar "CMDECHO" 0)
  (tcs:mkstyle "TCS-TEXT" "arial.ttf")
  (tcs:mkstyle "TCS-DIM" "arial.ttf")
  (tcs:mkdim "TCS-50" 50 1.0 0)
  (tcs:mkdim "TCS-100" 100 1.0 0)
  (tcs:mkdim "TCS-SITE-500" 500 0.001 3)
  (command "_.-DIMSTYLE" "_R" "TCS-100")
  (setvar "CMDECHO" oldecho)
  (princ "\nTCS-50, TCS-100 and TCS-SITE-500 created. TCS-100 is current.")
  (princ))

Working in Feet and Inches? (US Drawings)

If you draw for US clients, the same logic applies, only the numbers change:

Set Primary Units → Unit format: Architectural for building drawings, or Engineering (feet and decimal inches) for civil site work, and put the scale factor in Use overall scale of.

Common Problems and Fixes

10-Minute Practice Exercise: Dimension a Room and Plot

Use the plot you drew in Lesson 2’s exercise (20 m × 15 m plot with setback and driveway), or draw it fresh.

1. Run TCSDIM (or create styles manually as above).
2. Draw a room with 3000 × 3600 internal size and 230 mm walls. Add a 900 mm door and a 1200 mm window.
3. Make G-DIMS current and TCS-100 the current dim style.
4. Inner string: DLI on the first wall segment, then DCO across door and window.
5. Middle string: wall centre to wall centre.
6. Outer string: overall external size (should read 3460 and 4060).
7. Run DIMSPACE to space the three strings evenly.
8. Switch to TCS-SITE-500 and dimension the plot boundary. It should read 20.000 and 15.000.
9. Add a driveway width dimension (3.650) and a setback dimension.
10. On G-TEXT, write the room name “BED ROOM” with TEXT at 350 height (3.5 mm at 1:100) and a note with MLEADER: “230 THK BRICK WALL”.

If your overall dims read exactly 3460 and 4060, your drawing and your OSNAP habits are both correct.

Key Takeaways

• Draw at full size. Scale only annotation.
• Model text height = paper height × scale (2.5 mm × 100 = 250).
• Keep text style height at 0; control size from the dimension style.
• One dimension style per scale: TCS-50, TCS-100, TCS-SITE-500.
• Change ISO-25’s comma to a period.
• Dimension in three strings, on layer G-DIMS, using OSNAP.
• Never explode dimensions or type over their values.

AutoCAD Dimension and Text Style FAQs

What text height should I use for a 1:100 drawing in AutoCAD?

Use 2.5 mm on paper for notes and dimensions. In model space that is 2.5 × 100 = 250 units when you draw in millimetres. Room names usually use 3.5 mm (350 units).

What is DIMSCALE in AutoCAD?

DIMSCALE is the overall scale factor for dimensions, shown as “Use overall scale of” on the Fit tab. It multiplies text height, arrow size and gaps. Set it equal to your drawing scale, for example 100 for 1:100.

Should I use annotative dimensions?

Annotative dimensions resize automatically for each viewport scale and are excellent when you plot from layouts. If you are still plotting from model space, scale-based styles (like TCS-100) are easier to understand. We cover annotative scaling in Lesson 6 on layouts and plotting.

Why does my AutoCAD dimension show a comma instead of a decimal point?

The default ISO-25 style uses a comma as the decimal separator. Open DIMSTYLE, go to Primary Units and change Decimal separator to Period.

How do I show metres in dimensions when I draw in millimetres?

In Primary Units, set Measurement scale factor to 0.001 and precision to 0.000. A 12500 mm line will display as 12.500.

Which arrowhead is standard for civil drawings?

Architectural ticks (oblique strokes) are standard for building plans, sections and site plans. Closed filled arrows are common for RCC detailing, steel and leaders.

What is the difference between TEXT and MTEXT?

TEXT (DT) creates single-line labels and is best for room names and levels. MTEXT creates a paragraph box with formatting and is best for general notes and specifications.

How do I type the diameter symbol in AutoCAD?

Type %%c. For example, 10%%c @ 150 c/c displays as 10Ø @ 150 c/c. Use %%d for degrees and %%p for plus-minus.

Tired of setting up layers by hand? Use our free AutoCAD Layer LISP Generator and get every civil layer in one command.

Stuck on a setting? Ask in the Civil Forum and we’ll help you fix it.