Increase in Circumference
Calculation of the increase in circumference, diameter and radius of a circle or sphere.
Increase in circumference: Δc
A popular brain teaser is: when you lay a string around a glass and extend that string for one meter, how far is this string away from the glass now? 16 centimeters. And if you lay a string around the Earth and extend it for one meter, how far is it from Earth? Surprisingly also 16 centimeters. The distance from the object is the increase in radius, this only depends on the increase in circumference, it is independent of the object size.
Increase in diameter: Δd
Increase in radius: Δr
Δc = πΔd = 2πΔr
π, pi is 3.14159265
Δ, a capital Delta, is the common symbol for a difference.
Please enter one value, the other values will be calculated. The length unit is the same for all values, e.g. centimeter. Referring to the example above: an increase in circumference of 100 means an increase in radius of 100/(2π) = 15.91549431