How to Add Dimension in AutoCAD: Step-by-Step Guide

To add a dimension in AutoCAD, use the DIM command or select a dimension tool from the Annotate tab. Click the points or objects you want to measure, then place the dimension line where you want it to appear.

Syntax

The basic command to add dimensions in AutoCAD is DIM. You can also use specific dimension commands like DIMLINEAR for linear dimensions, DIMANGULAR for angles, and DIMRADIUS for circles.

Each command requires you to select points or objects to measure and then place the dimension line.

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DIM
DIMLINEAR
DIMANGULAR
DIMRADIUS

Example

This example shows how to add a linear dimension between two points:

1. Type DIMLINEAR and press Enter.
2. Click the first point.
3. Click the second point.
4. Move your cursor to position the dimension line and click to place it.

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Command: DIMLINEAR
Select first extension line origin or <select object>: (click point 1)
Select second extension line origin: (click point 2)
Specify dimension line location or <select object>: (move cursor and click to place)

Output

A linear dimension line appears between the two selected points showing the distance.

Common Pitfalls

• Forgetting to select the correct points can cause wrong measurements.
• Placing the dimension line too close or overlapping objects makes it hard to read.
• Using the wrong dimension command (e.g., using DIMANGULAR for linear measurements) leads to errors.
• Not setting the correct dimension style can cause inconsistent text size or units.

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Wrong way:
Command: DIMANGULAR
Select first extension line origin or <select object>: (click point 1)
Select second extension line origin: (click point 2)
Specify dimension arc line location: (incorrect for linear distance)

Right way:
Command: DIMLINEAR
Select first extension line origin or <select object>: (click point 1)
Select second extension line origin: (click point 2)
Specify dimension line location: (correct placement)

Quick Reference

Command	Purpose
DIM	General dimension command that lets you choose type
DIMLINEAR	Create linear (horizontal or vertical) dimensions
DIMANGULAR	Measure angles between two lines or points
DIMRADIUS	Dimension radius of circles or arcs
DIMDIAMETER	Dimension diameter of circles or arcs

Key Takeaways

Use the DIM or specific dimension commands like DIMLINEAR to add measurements.

Always select the correct points or objects before placing the dimension line.

Place dimension lines clearly to avoid overlapping and improve readability.

Choose the right dimension type for your measurement (linear, angular, radius).

Set dimension styles to keep consistent text size and units in your drawing.