Radial and azimuthal components of B field can be obtained from the x- and y-components of the field using the following formulas: B_r=cos(phi)*Bx+sin(phi)*By B_phi=-sin(phi)*Bx+cos(phi)*By In Maxwell you get B_r and B_phi using the fields calculator: Radial component (B_radial) Input > Quantity > B General > Smooth Vector > Scal? > ScalarX Input > Function > Scalar > PHI Scalar > Trig > Cos General > * Input > Quantity > B General > Smooth Vector > Scal? > ScalarY Input > Function > Scalar > PHI Scalar > Trig > Sin General > * General > + Select Add and set the name of expression as B_radial Azimuthal component (B_phi) Input > Quantity > B General > Smooth Vector > Scal? > ScalarX Input > Function > Scalar > PHI Scalar > Trig > Sin General > * General > Neg Input > Quantity > B General > Smooth Vector > Scal? > ScalarY Input > Function > Scalar > PHI Scalar > Trig > Cos General > * General > + Select Add and set the name of expression as B_phi