gramdang turns the labeled percentage and bottle size into the amount of the named ingredient, then divides the price by it. Same ingredient, same percentage, very different price per gram.
10 serums and creams, from 20 mg to 300 mg of retinol. With a price-per-mg calculator.
The formula, the rules, what we leave out, and the limits of label data.
Weekly price rankings for 69 Korean products (Coupang prices, in Korean): gramdang.com · Open data: CSV, JSON