You need to have one scale that you use as your "official" scale to accurately gauge your weight loss. Scales are calibrated differently and the flooring they are on can change the scale too. Weigh on the same scale, same time, same clothes (in the morning after waking up, before eating and after going to the bathroom is a good time). All the food you eat and drink all day has weight. You also have to think of the scale as a compass. It points you in the direction you need to go, but it doesn't tell the whole weight loss story. Losing fat/inches is another way to measure weight loss success. You can be at goal weight and still carry too much unhealthy fat and be flabby. I had a friend who went down 4 sizes but didn't see the scale move for months. Google "why the scale lies" for some insight. If you stay the same weight for a few weeks, than you know you are on a plateau. Otherwise it's quite normal to lose a pound or so a week. By the time you get to goal, you will look amazing. Muscle is leaner and denser than fat, so you can build muscle get smaller and stay the same on the scale. It will move again. Patience and persistence!