EXAMPLE: For Model # 228B, assume a radius desired of 12 inches. Calculate circumference of 3.14 (twice radius) 3.14*24= 75.36. Since the radius is over 10", divide by 4. Length of each piece is 75.36/4= 18.8". Model #228B is over 18" so the price of $3.80 is multiplied by 1.5. $3.80*1.5= 5.70 per curve.