A theoretical approach to a quantitative assessment of the stability of topologically
stabilized structures to thermal fluctuations and random external disturbances is proposed. It is
based on the theory of transition states for magnetic degrees of freedom and in the harmonic
approximation allows calculating the lifetimes of magnetic states. The results of calculations of the
rates of nucleation and annihilation of magnetic skyrmions of various sizes from several
nanometers to microns are presented. The problem of taking into account the long-range dipole
interaction when calculating the lifetimes of micron systems with atomic resolution is considered.