This study explores the biometry of Cardisoma crassum individuals presented in two folkloric festivals within the Montijo Gulf in 2022 and 2023. Crabs in the Rio de Jesús (RJ) festival from 2022 exhibited a male biased sex ratio, contrasting Montijo's (MO) even sex ratio in 2023. Carapace widths were similar between festivals (RJ, 65.59 ± 6.56 mm; MO: 64.29 ± 5.92 mm). Sex-based size variations were consistent within years but not between years. Localities showed significant size and sex ratio differences, while transportation distance to the festival venues did not correlate with crab size. Additionally, a comparison between current data and previous studies from 2014–2015, 2021 and 2022, highlighted size differences among sites might not be related to yearly increasing crab demand; instead, site-specific extraction pressure may be an underlying factor. Festivals consumed approximately 198 crab bundles in Rio de Jesús in 2022 (≈ 2,376 individuals) and an estimated 207 bundles in Montijo in 2023 (≈ 2,484 individuals). This study unveils complex dynamics in C. crassum populations at the local level, encompassing sex ratios, size variations, and economic dimensions within festival contexts. Understanding these multifaceted dynamics is crucial for effectively managing these coastal crab populations in the future.