Dimension Radius

The dimradius command places a radius dimension on an arc or circle. The dimension line runs from the center to a point on the circumference in the cursor’s direction, labeled R <value>. To dimension a full diameter instead, use Dimension Diameter.

Anatomy of a radius dimension

  ● (center)
   \
    \  R 5.00
     \
      ●────── text (cursor side)
   (arc point)

Dimension line — from center through an arc point toward the cursor, with an arrowhead at the arc.
Label — R followed by the radius value.

Placing a radius dimension

Type dimradius in the terminal or click the Dimension Radius toolbar button.
Click an arc or circle to select it.
Move the cursor to orient the dimension line — the arc-point tracks the cursor direction from the center.
Click to place the dimension.

Only Arc and Circle entities can be selected. Clicking any other entity type does nothing.

Keyboard reference

Key	Action
`Escape`	Cancel

Dimension Radius vs Dimension Diameter

	Dimension Radius	Dimension Diameter
Measures	Radius (center to edge)	Diameter (edge to edge through center)
Dimension line	Center → arc point	Arc point → arc point (through center)
Label prefix	`R`	`⌀`
Arrowheads	One (at arc point)	Two (at both arc points)
Best for	Annotating one side of a curved feature	Annotating full circular dimensions

Editing the label — simple mode

Double-click a placed radius dimension to open the text editor in simple mode. The editor is pre-seeded with the current rendered value (e.g. R 5.00) so you can position the cursor and edit it directly.

Feature	Behaviour
Bold / Italic / Font / Height	Apply to the entire label at once
Per-character formatting	Not supported
`Enter`	Commits the value and closes the editor
Multi-line	Not supported

See Text Editor — simple mode for the full reference.

DXF — DIMENSION radius entity

Radius dimensions are saved as DIMENSION entities with radius-type geometry, storing the center coordinates, the arc-point position, and the measured radius value. All properties round-trip without loss.

Unit format and precision

The Unit Format property in the property window chooses how the measurement is written: Scientific, Decimal (the default), Engineering, Architectural, Fractional, or System, which follows your system’s number style. Precision lists its choices the way the chosen format writes them — fractions of an inch for Architectural and Fractional, for example. A DXF’s own unit format is read in, and new dimensions take both settings from the current DimensionStyle. Fractions are written on one line, not stacked.

Dimension style

New radius dimensions copy the current DimensionStyle, including the second arrowhead, center-mark type and size, text, precision, gap, alignment, and frame. The values are copied at creation time rather than live-linked.