About how many calories have I worked off and eaten today?

Get a heart rate monitor and it will keep track of your calories for you. We cannot answer this for you because it all depends on the intensity at which you worked out. Two people can do the exact same work out you described and 1 person can put little or no effort into it and the 2nd person could have been at 70% cardiovascular capacity. It is safe to say that you have clearly burned off the calories you've eaten for the day - digestion alone plus your heart at resting rate would have burned off how little you've eaten for the day.