How do you figure out how much trim is needed to go around the outer edge of a tutu?
Of course, the easy answer is, “Just measure it.” But if that doesn’t work for you, think back to middle school algebra to find the circumference (outer edge, perimeter, border, rim) of a circle. Remember Pi - 3.14 (more or less)?
Simply multiply Pi (3.14) x the diameter of your tutu, or multiply 2 x Pi x the radius. Both equations will give you the same answer, so use which ever one is the easiest measurement for you to find. The diameter is 2 x the radius, or in the case of a tutu, it is the distance from one edge of the tutu straight across to the other edge.
Be sure to flatten/tuck in the bodice and basque so you get an accurate result. The radius is the distance from the center of the tutu out to its’ edge. In most cases, when dealing with tutus, it is easiest to accurately find the diameter rather than the radius.