This study proposes a metric that builds upon the Lorenz curve and the Gini coefficient to measure litter distribution on beaches. We address not only the degree of litter distribution but also the causes in relation to litter abundance as well as to a wide range of geographic and climatic factors. We analyze a beach survey dataset that contains 10,262 records of litter counts for 1,803 beaches in the UK from 2000 to 2016. We found that litter distribution varies by litter type, with plastic and pottery being the least and most concentrated on beaches, respectively. A certain degree of litter distribution is due equally to litter abundance on both small and large beaches regardless of litter types. We also found location and seasonality have relatively larger effects on the overall distribution of beach litter while the effects of climatic conditions are negligible.