How much laundry detergent is used globally each year?

Estimating global laundry detergent usage requires breaking down the problem into manageable assumptions. First, consider the world population and estimate the percentage that actively uses laundry detergent, excluding those who use alternative cleaning methods or only water. Then, segment the detergent-using population by washing frequency (e.g., daily, twice weekly, weekly). Finally, assign an average detergent amount per wash for each segment and sum the results to arrive at a global estimate. For instance, with 8 billion people, assuming 90% use detergent (7.2 billion), and then categorizing them into daily, twice-weekly, and weekly washers, with varying detergent amounts per wash (e.g., 5g, 10g, 15g respectively), allows for a calculated total.