How To Find the Center of a Circle
This is a handy trick that I learned for finding the center of a circle.
I made my girlfriend and I phone holders with steel discs for their bases. I had to drill and thread a center hole in each base for the articulating arms.
To figure out where I needed to the drill the center of the hole at, I used the method detailed below.
Materials needed:
- Ruler
- Sharpie marker
Step #1:
Make two equal length lines parallel to each other on the circle. In my case, I chose to use 3” long lines. So on the top of the circle, find where its width is 3” and make a straight line across. Then on the bottom of the circle, find where its width is 3” and make a straight line across there, too. You can use any width you’d like, as long as they’re the same length.
Step #2:
Once you have two equal length lines parallel to one another, you can then connect them as pictured. You’re making an X between the two lines.
Step #3:
You’re all done. Where the two lines of the X meets will be the center of the circle.
