  We study entropy corrections due to thermal fluctuations for asymptotically
AdS black holes in the grand canonical ensemble. To leading order, these can be
expressed in terms of the black hole response coefficients via fluctuation
moments. We also analyze entropy corrections due to mass and charge
fluctuations of R-charged black holes, and our results indicate an universality
in the logarithmic corrections to charged AdS black hole entropy in various
dimensions.
