Needs["ErrorBarPlots`"];

data = Import[
   "C:\\Users\\User\\Documents\\DELETE\\Coil_DataWU.csv", "CSV"];
mu = 4 e - 7*Pi;
Radius = 0.149;
radius = 0.0582;
frequency = 8313;
field [d_?NumericQ, r_?NumericQ, x_?NumericQ] :=
  mu*frequency*
   Sqrt (2)/(2*Pi*
      Sqrt (x^2 + (Radius + r)^2))*((Radius^2 - x^2 -
         r^2)/(d^2 + (r - Radius)^2)*
      EllipticE (Sqrt (4*r*Radius*(x^2 + (Radius + r)^2)^(-1))) +
     EllipticK (Sqrt (4*r*Radius*(x^2 + (Radius + r)^2)^(-1))));
solution =
  FindFit[data, (2*i*Pi*Integrate[{field}, {r, 0, radius}]), {i}, x];