How much laundry detergent do I use?

i just started living by my self and i dont know how much detergent to use for 1 weeks worth of clothes. Thats like 3 trousers, 5 shirts, 7pairs of underwear, and a set of pjs. I was tolded to use a whole spoon full of detergent that comes with the box(like 8Tbsps) but i dont know if thats right.