Thermostat Setback Savings Calculator

About this calculator

The calculator is built on the well-known heating rule of thumb popularized by U.S. Department of Energy field studies: for roughly every degree you set the thermostat back for an 8-hour stretch, you save about 1% on your heating bill for that period. The relationship is close to linear over the modest setbacks most households actually use — a few degrees overnight or while the house is empty during the workday — because heat loss through walls, windows, and roof scales with the difference between indoor and outdoor temperature, so a lower indoor target means slower, cheaper heat loss.

Programmable and smart thermostats made this kind of scheduled setback routine, and homeowners use a savings estimate like this one to decide whether a nightly or daytime setback is worth the temporary chill, and to set realistic expectations before buying a smart thermostat marketed on energy savings. The actual percentage saved varies with climate, insulation quality, and how efficiently the furnace responds to recovery, but the 1%-per-degree-per-8-hours figure remains the standard back-of-envelope estimate used by energy advisors.

Enter your current annual heating cost, how many degrees you plan to set back the thermostat, and for how many hours a day, and the calculator returns the estimated dollar savings.