Setting your thermostat is a very personal decision. There are no fixed rules - - your settings largely depend on your own comfort. On average, for every degree you set back your thermostat, you can save 6% on your energy bill. And keep in mind, the average household spends about $2,000 a year on energy bills - nearly half of which goes to heating and cooling.
Through aggressively setting back and setting up your thermostat you can save about $180* every year in energy costs for a typical, single-family home, compared to leaving the home comfortable all the time. Experiment with adjusting the temperature to see what is right for you and your family.
*The $180 savings assumes an 8-hour daytime setback and a 10 hour nighttime setback of 8 degrees F in winter and 4 degrees F in summer.