Measuring Geometry

Read the length, radius, angle, area or separation of what you've drawn with Measure — without adding anything to the drawing.

Sometimes you just need to know how big something is. Measure reads the size of the selected geometry and tells you, without adding a dimension or changing the drawing in any way.

Use Measure to ask a question. Use a dimension (Dimensioning a Drawing) when the number should be on the drawing.

Prerequisites

Before you begin, ensure that:

You have some geometry drawn and can select it with the Select tool.

Measuring

Shortcut: Ctrl+Shift+M · Tools → Measure

Select one entity, or two to measure between them.
Press Ctrl+Shift+M, or choose Tools → Measure.
The result appears in the prompt on the Tool Options row, starting with what was measured — for example:
```
line — length 50.00   angle 30.0°   dx 43.30  dy 25.00
```

Nothing is added to the drawing, nothing is selected or deselected, and there is nothing to undo. Change the selection and measure again as often as you like.

With nothing selected the prompt says "Measure: select one entity, or two to measure between them"; with three or more it tells you how many are selected.

What It Reports

One entity

Selected	Reported
Line	Length, direction angle, and dx / dy between its ends
Circle	Radius, diameter, circumference, area, and centre position
Arc	Radius, diameter, arc length, swept angle, and centre position
Point	Its position

Two entities

Selected	Reported
Two points	Distance, angle, dx / dy
Two lines	The acute angle between them — or, if they're parallel, the distance between them
A point and a line	Distance from the point to the line
Two circles or arcs	Distance between their centres, dx / dy
A circle or arc and a point	Distance from the centre to the point, dx / dy
A circle or arc and a line	Distance from the centre to the line

Anything else — an ellipse, for instance — reports that it can't be measured yet.

Note: three answers that are deliberate

An arc reports its arc length, the distance actually drawn along the curve — not the circumference of the circle it belongs to.

Two lines report the acute angle. Asking the angle between two lines means 10°, never 170°.

A point-to-line distance is to the drawn segment, not to the line extended to infinity. Past the end of the line, you get the distance to its nearest endpoint.

Lengths are reported to two decimals and angles to one — the same precision dimension labels use, so a measurement and a dimension beside it agree.

Next Steps

You now know how to:

Measure one entity, or the relationship between two, with Ctrl+Shift+M
Read what each kind of selection reports
Know why an arc gives its arc length and two lines give the acute angle

Next: Reading Your Sketch