Making good use of my bathroom scale

I will be going to China on the November 2. This time I will be going to Guilin - a place famous for its breathtaking scenery.

Before the trip, I had to do some preparation such as packing what needs to be taken. I also check the weather every day through Weather Yahoo so that I can bring along thicker clothing in case the weather turns too cold for me.

According to my tour agency, we can bring only 20kg of luggage, 5 kg of hand luggage and 1 kg of liquid medicine or cosmetics to be put in transparent bags for checking purposes.

How do I know whether my luggage is overweight? I had an idea to find this out. I put the luggage on my bathroom scale (weighing machine) and it showed only 12 kg.

How useful is my bathroom scale this time!