Your waist line measurements should be taken at the navel in a "relaxed state". REMEMBER THAT without proper dieting and a modification in you current eating habits, it will be much more difficult to reduce the waistline in size.
As a general rule of thumb, for every 7lbs of weight loss, there should be about 1" or 1 belt notch of reduction in this area. You cannot really "spot reduce", so abnormal amounts of abdominal exercises can be a real waste of time. An overall training program is advised.
In addition to eating modifications, an increase in aerobic exercise is needed. There are a wide variety of possibilities. Stair climbers, bikes, treadmills, cross trainers and elliptical machines are just a few of the many machines out there. Most are equipped to help monitor your progress. Some even calculate your distances, efforts and heart rate. You can interchange with the different machines for a variety of workouts.
Running or jogging is another way to help trim off the extra inches. I do not advise running if you have just begun an exercise program or if you are currently over weight. There is a lot more to this activity than what meets the eye.
If you decide to run, make sure that you have a proper pair of running shoes made for jogging/running. Simple "court shoes" don't give you the proper support needed to progress without a possibility of injury. If you have experienced ankle, knee, shin, back or neck problems, or if you are overweight or obese, DON’T RUN. This exercise puts an enormous amount of stress and strain on your joints, tendons, ligaments and skeletal frame. Try the machines instead.