Solar Rotation Formula

Equation for calculate solar rotation is,

ω = A + B × sin (ϕ)² + C × sin (ϕ)⁴

where,
A, B, C = constants
ϕ = solar latitude
ω = angular velocity

A current set of accepted average values

A = 14.713 ± 0.0491 °/d
 B = -2.396 ± 0.188 °/d
 C = -1.787 ± 0.253 °/d