Maybe not quite what you're after, but slide 85 of NASA's Aerothermodynamics Lecture has this figure:
Of course this requires an estimate of instantaneous heat flux along the entry trajectory (integrated into total heat load). A good value for total heat load for a LEO reentry is ~$10^4$ to $2$x$10^4$ $\frac{J}{cm^2}$ which translates to ~10-15% of the entry vehicles mass as TPS (thermal protection system).
This is of course just a 1st (maybe even 0th) order design estimation tool, and specific to ablative entry systems which are generally not reusablewhich are generally not reusable.