Although the quantity of pornography use (QPU, i.e., frequency/time spent on pornography use) has been positively associated with the severity of pornography use (i.e., problematic pornography use, PPU), the magnitudes of relationships have varied across studies. This meta-analysis aimed to assess the overall relationships and identify potential moderating variables to explain the variation in these associations between QPU and PPU. We performed a literature search for all published and unpublished studies from 1995 to 2020 in major online scientific databases up until December 2020. Sixty-one studies were identified with 82 independent samples involving 74,880 participants. Results indicated that there was a positive, moderate relationship between QPU and PPU (r = 0.34, p < .001). The strength of relationship significantly varied across measures of PPU based on different theoretical frameworks, indicators of QPU, and sexual cultural contexts (conservative vs. permissive sexual values). Frequency was a more robust quantitative indicator of PPU than time spent on pornography use. In conservative countries, QPU showed more robust association with self-perceived PPU. Future studies are encouraged to select the measurement of PPU according to research aims and use multi-item measures with demonstrated content validity to assess pornography use. Cross-cultural (conservative/permissive) comparisons also warrant further research.