The cost of laundry detergent depends on the product brand and the bottle size. Typically, laundry detergent bottles cost between $3 and $6. That typically provides for as many as 32 loads of wash in the United States. A bottle of laundry detergent for 64 loads may cost $11.50. On an average, the cost of laundry detergent is approximately $0.16 per load. Some of the renowned laundry detergent brands include Tide, All, Surf and Wisk.