Why round bar dia calculator with different number for same area in a same width need?

Some times we can not use random number due to links bar, so we will take manageable number and calculate dia of bar.

What is the round bar dia calculator with different number for same area in a same width formula?

d1= Round bar-1 dia
n1= Round bar-1 number
n2= Round bar-2 number
Let round bar-2 dia, d2
For same area of round bar in particular breadth (b) of any structure-
Area-1 = Area-2
(π*d1^²*b*n1)/(4) = (π*d2^²*b*n2)/(4)
(d1^²)*(n1) = (d2^²)*(n2)
d2 = (n1/n2)^^0.5*(d1)