The amount of laundry detergent to use for a load of laundry depends on several factors, including the type of washing machine, size of the load, how soiled the clothes are, hardness of your water, and concentration of the detergent. For example, high-efficiency washers use less water, so if you put in too much detergent, it won’t get dissolved. On the other hand, if you have a really big or heavily-soiled load, you’ll need to use more. Carefully read the instructions for use on the laundry detergent packaging so you know the right amount to use.