  The extraction of the magnetic form factor of the nucleon at zero momentum
transfer is usually performed by adopting a parametrization for its momentum
dependence and fitting the results obtained at finite momenta. We present a
position space method that allows us to remove the momentum prefactor in the
form factor decomposition and hence compute the magnetic form factor directly
at zero momentum without the need to assume a functional form for its momentum
dependence. The method is explored on one ensemble using $N_f=2+1+1$ Wilson
twisted mass fermions with a light quark mass corresponding to
$M_\pi\approx373\mathrm{GeV}$ and a lattice spacing of
$a\approx0.082\mathrm{fm}$. We obtain results for the isovector magnetic moment
and for the proton and neutron magnetic moments. The value we find for the
isovector magnetic moment is larger as compared to fitting the form factor at
the discrete values of the lattice momentum transfers using a dipole Ansatz,
bringing it closer to the experimental value.
