The first part of this evaluation will require you to take note of your emotions. Since your emotions often change with each moment, you will have to track them often. At the end of each day, review the emotions that you experienced during that day.
Note them down in a journal or notebook, and do this at different points in the entire day. Repeat this for thirty days. Over time, the day to day variances in your emotional state will be eliminated. When the month ends, you will have a good understanding of your emotional state and actually how happy you are. This might take you just about five minutes each night.
Becoming aware of how your emotions work is a much more accurate way of measuring your happiness than thinking about how you feel.