We propose using the Wasserstein-2 distance (W₂) as an alternative to the widely used Kolmogorov–Smirnov (KS) statistic for analysing distributional data in geochronology. W₂ measures the horizontal distance between observations, while KS measures vertical differences in cumulative distributions. Using case studies, we find that W₂ is preferable in scenarios where the absolute age differences in observations provide important geological information. W₂ has been added to the R package IsoplotR.