A Business Insider column noted that two-thirds of the bottled water sold in the United States is in individual 16.9-ounce bottles, which comes out to roughly $7.50 per gallon. That’s about 2,000 times higher than the cost of a gallon of tap water.
And in an article in 20 Something Finance, G.E. Miller investigated the cost of bottled versus tap water for himself. He found that he could fill 4,787 20-ounce bottles with tap water for only $2.10! So if he paid $1 for a bottled water, he’d be paying 2,279 times the cost of tap.