Circumference Calculator
This calculator requires the use of Javascript enabled and capable browsers. PI is approximately 3.14, by definition, the number of times that a circle's diameter will fit around the circle. PI goes on forever, and can't be calculated to perfect precision, although you can do better than 2 decimal places. On our site and in all of our calculators, 3.14159 is the value we use, unless otherwise specified. The purpose of this calculator demonstration is to calculate the circumference of a circle. To use this calculator, begin by entering the diameter of a given circle and PI. Click on the "Calculate" button for the returned calculated value of he circle's circumference. The default values are those used by Chinese math major, Tsu Ch'ungChi in his 500AD calculations. The formula for determining the circumference of a given circle is the diameter multiplied by PI. Please see our Piece Of PI information, and our Historical Computation Of PI Table. Dividing the PI(e) has always been a problem but sometimes multiplying with it is also. You can do either here; PI power is also available. Calculate the diameter here; Calculate PI here. (Please don't leave crumbs on the table.)
Updated 8.12.11

