Polygon Diagonals Calculator for layout notes, drafting, and classroom geometry when you want a fixed formula answer without improvising the math by hand.
Informational calculator only. Verify important outputs independently before legal, tax, medical, engineering, safety-critical, contractual, employment, or compliance use.
Enter job values, review the estimate, then use the decision hints before ordering or quoting.
diagonals = n(n - 3) / 2Subtract the sides and the point itself from every vertex connection count, then divide by two.
The polygon must have at least three sides.
Keep more precision when the output will feed another formula, drawing, coordinate step, or comparison rather than being rounded once and left alone.