So a friend just asked me if there's a way to dimension a circumference....not doing the calculation yourself and adding it as a note. I'm stumped on this one. Any suggestions?

- You might have to dimension a portion of the circumference, like maybe half of it, with the other half coradial. Pick the arc's endpoint, the arc itself, then the arc's other endpoint to dimension an explicit arc length. (circumference/2 in my example)
- I'd create a dim in the sketch with the diameter of interest as attached. Make the equation by double clicking the dimension to be controlled (the dim of the line). to the right of the modify value is a drop down. In the drop down list is "add equation". Use an equation like in the picture. When you want the circumference in the drawing note, link to the line length instead of the circle dimension
thanks brian. hopefully my new computer will arrive tomorrow. as of right now i don't have access to solidworks until then. the only thing left to explain i think is linking to the equation in the drawing. I can't remember off-hand how to do it but i know you can. i'll fiddle with it when i get a chance unless someone beats me to it.

Create equation in part: "circumference"=D1@Sketch1 * pi (where D1@Sketch1 is the diameter)

Next create custom property in part: Property Name - circumference, Type - text, Value/text expression - "circumference@XYZ.slprt " (this should be in pulldown menu.

Next create drawing and add annotation linking to property.

See image.

Just for giggles, I did the following experiment:

- Draw an arc
- Add an arc length dimension (endpoint + endpoint + segment, for the unschooled)
- Make dimension driven
- Drag arc endpoints, ensure watch what happens with dimension
- Drag endpoint of arc to other endpoint to close circle
- RESULT: dimension detaches, reads ".
*000*", and can not be deleted.

Create equation in part: "circumference"=D1@Sketch1 * pi (where D1@Sketch1 is the diameter)

Next create custom property in part: Property Name - circumference, Type - text, Value/text expression - "circumference@XYZ.slprt " (this should be in pulldown menu.

Next create drawing and add annotation linking to property.

See image.