We want to find the circumference of each tire
The circumference formula is
C = 2*pi*r where r is the radius
Assuming R means radius in the tire formula
P210/55R15
C = 2 * pi * 15 = 30 * 3.14 =94.2
P240/65R16
C = 2 * pi * 16 = 32 * 3.14 = 100.48
Taking the difference
100.48 - 94.2 =6.28
