"Many people guestimate here and while it may seem like no biggie, too much detergent will prevent your towels from rinsing clean. We advise measuring out the amount of detergent exactly to the manufacturer's specifications — knowing that less is frequently more. A "medium" load translates to roughly six to seven pounds of laundry and fills 3/4 of a household machine. A larger laundromat load will require a bit more."