We characterize magnetic fields produced during electroweak symmetry breaking by nondynamical numerical simulations based on the Kibble mechanism. The generated magnetic fields were thought to have an energy spectrum k3 for small wave numbers k, but here we show that it is actually a spectrum k4 along with characteristic fluctuations in the magnetic helicity. Using scaling results from magnetohydrodynamics simulations for the evolution and assuming that the initial magnetic field is coherent on the electroweak Hubble scale, we estimate the magnetic field strength to be ∼10-13 G on kpc scales at the present epoch for nonhelical fields. For maximally helical fields we obtain ∼10-10 G on Mpc scales. We also give scalings of these estimates for partially helical fields.