Compte tenu de l'expression du tenseur métrique en coordonnées sphériques, le gradient g i j f ; i e j {\displaystyle g^{ij}f_{;i}\mathbf {e} _{j}} d'un champ scalaire f {\displaystyle f} s'écrit
∇ f = ∂ f ∂ r e r + 1 r 2 ∂ f ∂ θ e θ + 1 r 2 sin 2 θ ∂ f ∂ ϕ e ϕ {\displaystyle \nabla f={\frac {\partial f}{\partial r}}\mathbf {e} _{r}+{\frac {1}{r^{2}}}{\frac {\partial f}{\partial \theta }}\mathbf {e} _{\theta }+{\frac {1}{r^{2}\sin ^{2}\theta }}{\frac {\partial f}{\partial \phi }}\mathbf {e} _{\phi }}
Soit, dans la base orthonormée
∇ f = ∂ f ∂ r e r + 1 r ∂ f ∂ θ { e θ r } + 1 r sin θ ∂ f ∂ ϕ { e ϕ r sin θ } {\displaystyle \nabla f={\frac {\partial f}{\partial r}}\mathbf {e} _{r}+{\frac {1}{r}}{\frac {\partial f}{\partial \theta }}\left\{{\frac {\mathbf {e} _{\theta }}{r}}\right\}+{\frac {1}{r\sin \theta }}{\frac {\partial f}{\partial \phi }}\left\{{\frac {\mathbf {e} _{\phi }}{r\sin \theta }}\right\}}