Dimension Styles Reference

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Scaling Method

DIMSCALE multiplies all dim variables

Drawing Scale

Plotted Text Height

Discipline Units

DIMSCALE 48

DIMTXT (model height) 6"

DIMASZ (arrow size) 6"

DIMGAP (text gap) 1.8"

DIMEXO (ext offset) 1.8"

CANNOSCALE 1/4"=1'-0"

Live Dimension Preview — Model Space representation at chosen scale

Computed Dimension Variables — Set These in DIMSTYLE

DIMSCALE vs Annotative — Which to Use

Two fundamentally different approaches exist for scaling dimensions. DIMSCALE is the old-school method — it multiplies every dimension variable by a single overall scale factor, so you set DIMSCALE=48 for 1/4"=1'-0" and everything scales up. Annotative is the modern approach — the dim style holds the plotted size and AutoCAD automatically scales it up based on the current annotation scale. Use annotative if you have multiple viewports at different scales showing the same geometry. Use DIMSCALE if you have a simpler drawing with one scale throughout.

Annotative Dimension Style Modern — Recommended

Enable "Annotative" in DIMSTYLE
Set values at plotted size (e.g. DIMTXT = 0.125")
AutoCAD scales up automatically per CANNOSCALE
One dim style works across multiple viewport scales
Annotation scale must be set per viewport
Best for multi-scale sheet layouts
Dims must have the right scale added (right-click → Add Current Scale)

DIMSCALE Method Classic — Simple setups

Create a separate dim style per scale
Set DIMSCALE = Scale Factor (e.g. 48)
DIMTXT × DIMSCALE = model space height
Simple to understand and troubleshoot
One scale per drawing or viewport
Must create new dim style for each scale
Best for single-scale drawings

Step-by-Step: Creating a Dimension Style

Open Dimension Style Manager Type DIMSTYLE (or D) → click New → name your style (e.g. "ARCH-1/4" or "ANNOTATIVE-STD").

Lines tab — extension lines and dim lines Set Extension line offset (DIMEXO) and Extension beyond dim line (DIMEXE). Baseline spacing for stacked dims. Use the computed values from the result band above.

Symbols and Arrows tab Set arrow style (Closed Filled is standard) and arrow size (DIMASZ). For civil drawings, Tick marks are common. Set center mark size.

Text tab Set text height (DIMTXT) — use plotted height for annotative, or plotted × scale factor for DIMSCALE method. Set text placement and alignment. "Aligned with dimension line" is standard for linear dims.

Fit tab — Overall Scale If using DIMSCALE method, set "Use overall scale of:" to your scale factor. If using Annotative, check "Annotative" checkbox and leave scale at 1.

Primary Units tab Set unit format (Architectural, Decimal, Engineering, Scientific). Set precision, suppression of zeros, prefix/suffix. For architectural: Feet & Inches, suppress trailing zeros.

Set as Current and Apply Click OK → Set Current → Close. New dimensions will use the new style. Use DIMREASSOC to update existing dims if needed.

Standard Preset Dimension Styles

Complete Dimension Variable Reference

Variable	Description	Typical Base Value	Controls
DIMSCALE	Overall dimension scale factor	= Scale Factor (e.g. 48)	Multiplies all size variables when not using annotative
DIMTXT	Text height in dimension	0.125" / 3.5mm	Plotted text height; ×DIMSCALE in model
DIMASZ	Arrow size	0.125" / 3mm	Length of arrowhead or tick mark
DIMGAP	Gap between text and dim line	0.0625" / 1.5mm	Text frame gap; also controls text box size
DIMEXO	Extension line offset from origin	0.0625" / 1.5mm	Gap between measured point and start of ext line
DIMEXE	Extension beyond dim line	0.125" / 3mm	How far ext line extends past the dim line
DIMBLK	Arrow block name	CLOSED_FILLED	Style of arrowhead (Closed, Open, Tick, Dot, etc.)
DIMBLK1 / DIMBLK2	Different arrows each end	Same as DIMBLK	Different arrow style for each dimension end
DIMTAD	Text above dim line	1 (above)	0=centered, 1=above, 2=outside, 4=JIS
DIMTVP	Text vertical position	0	Offset from dim line when DIMTAD=0
DIMJUST	Text horizontal justification	0 (center)	0=center, 1=left ext, 2=right ext, 3=above first ext, 4=above second
DIMLUNIT	Linear unit format	2 (decimal) / 4 (arch)	1=scientific, 2=decimal, 3=engineering, 4=arch, 5=fractional
DIMDEC	Decimal places (linear)	4 (dec) / 0 (arch)	Precision of linear measurements
DIMDSEP	Decimal separator	. (period)	Character used as decimal separator
DIMZIN	Zero suppression	8 (arch) / 0 (metric)	Controls display of leading/trailing zeros
DIMRND	Rounding value	0 (none)	Round all linear dims to this increment
DIMPOST	Prefix / suffix	(none)	Text before/after measurement. Suffix: "; prefix: text<>"
DIMCLRD	Dimension line color	BYLAYER	Color of dimension lines
DIMCLRE	Extension line color	BYLAYER	Color of extension lines
DIMCLRT	Dimension text color	BYLAYER	Color of dimension text
DIMDLE	Dim line extension (tick)	0.125" (for ticks)	Extends dim line past ext line when using tick arrows
DIMDLI	Baseline spacing	0.375" / 10mm	Distance between parallel baseline dims
DIMTOFL	Force dim line between ext lines	1 (on)	Draws dim line even when text is outside ext lines
DIMSOXD	Suppress outside extension dim lines	0 (off)	Hides ext lines when text outside
DIMFRAC	Fraction format	0	Fraction style: 0=horizontal, 1=diagonal, 2=not stacked
DIMLTYPE	Dimension line linetype	BYLAYER	Linetype for dimension lines
DIMLTEX1/2	Extension line linetypes	BYLAYER	Individual extension line linetypes

Arrow Block Names

DIMBLK Value	Appearance	Common Use
CLOSED_FILLED	Solid filled arrowhead ◀	Architectural, mechanical, general
CLOSED	Hollow arrowhead ◁	Mechanical drawings, ISO
OPEN	Open arrow ‹	General, clean look
OPEN30	30° open arrow	Compact spaces
_OBLIQUE	Tick/slash ╱	Architectural, civil, AIA standard
_DOT	Filled dot ●	Radial dims, detail circles
_DOTSMALL	Small dot	Compact dims, chain dims
_DATUMFILLED	Filled datum triangle ▼	GD&T datum references
_INTEGRAL	Integral symbol ∫	Architectural chain dims
NONE	No arrowhead	Leader lines, custom terminations

Common Mistakes & Fixes

Problem	Cause	Fix
Dim text too small / too large to read	Wrong DIMSCALE for the drawing scale	Set DIMSCALE = scale factor; recalc using this page
Annotative dims not showing in viewport	Annotation scale not added to dim	Select dim → right-click → Annotative Object Scale → Add Current Scale
Dimension measures wrong value	DIMLFAC not = 1 (unit conversion factor)	Check DIMLFAC; set to 1 unless intentional conversion
Dims show decimal instead of feet/inches	DIMLUNIT not set to Architectural (4)	In DIMSTYLE → Primary Units → set to Architectural
Trailing zeros in feet (3'-0")	DIMZIN not set for zero suppression	Set DIMZIN = 8 to suppress trailing 0" in architectural
Text overlaps dim line	DIMGAP too small or DIMTXT too large	Increase DIMGAP; reduce DIMTXT; adjust fit options
Different style on different dims	Dim style override active	Type DIMSTYLE → Overrides → Clear all overrides
Changed DIMSTYLE but dims didn't update	Dims reference old style	Select dims → Properties → change to correct style, or use DIMREGEN

Questions & Tips

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AutoCAD 2024 Dimension Styles Reference — Anthony Squires • Senior Drafter • 2026 — Back to Reference Card

Disclaimer: The information provided on this site is for general reference and educational purposes only. While every effort has been made to ensure accuracy, all calculations, standards, specifications, and reference data should be independently verified before use in any professional, engineering, or construction application. This site is not affiliated with Autodesk, SDG&E, NESC, NEC, or any other referenced organization or standards body. SDG&E manual content (OHCS, EDD, UGCS) is reproduced for reference only — always consult the current official SDG&E documentation for construction decisions. Nothing on this site constitutes professional engineering advice. Anthony Squires and the contributors to this site accept no liability for errors, omissions, or damages arising from reliance on any information contained herein. Use at your own risk.

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