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Drawing an Ellipse: The String Method

Step-by-step instructions for drawing an ellipse with the string method—a complimentary Quick Reference Guide to TiC full-length articles, The Elegant Ellipse and Finding the Right Angle.Full Ellipse-string method


8 Responses to “Drawing an Ellipse: The String Method”

  1. David

    What a great set of simple instructions. After watching dozens of videos with exhaustive instructions it is a breath of fresh air to see this laid out this way. I am doing this ellipse on a 4×8 ft steel sheet and welding the rods to it. I am using wire instead of string and then taking my plasma cutter to it. I am excited to see the results. Thank you again.

  2. Brad

    So clear and so practical. Like David, I just watched 30 minutes worth of videos and this is the most straightforward explanation I have seen. My fire pit cover will be more refined thanks to you!

  3. Lee

    This works great, but it’s not clear how to establish point C here. The center peak (point C) should be 1/6 of the overall width. So for a 60″ wide cased opening, the center would be 10″ above the major axis or spring line. For a 48″ wide opening, the center would be 8″ above the spring line and so on. In other words a 6:1 ratio for the rise relative to the overall length.

    • Wm. Todd Murdock

      This method covers drawing an ellipse with known dimensions.
      For an opening with a semi-elliptical head, point C is located at the desired rise above the midpoint of the spring line (major axis).

      As far as a fixed relationship between height and width, I’ve seen countless examples in both classically inspired and modern architecture that fall outside the 6:1 ratio.

  4. David Culp

    Very helpful. I was trying to find the proper ellipse to fair the line from my wingtip nosepiece to the tip, if you can imagine 1/4 of an ellipse. It worked beautifully, once I understood it. My semi-major axis was 8” and my semi-minor axis was 4.5”. Thank you.

  5. Betsy

    Great. Using for a science experiment on ellipses as studying Kepler. Yes better than all those videos.


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