Smart Thermostat Savings Calculator
Cost, yearly energy savings, and payback for a smart thermostat.
Basic: Nest Thermostat, ecobee Essential. Mid-range: ecobee Enhanced. Premium: ecobee Premium, Nest Learning Thermostat.
Most smart thermostats need a C (common) wire for power; older systems often lack one.
Enter your own from your utility bills: heating fuel plus the cooling share of your electric bill. The default, $900, is ENERGY STAR's figure for an average U.S. household.
Many utilities offer a rebate on ENERGY STAR certified smart thermostats.
How to use this calculator
Pick a thermostat price tier and how it will be installed, say whether your bill is mostly heating, mostly cooling, or about even, and enter your annual heating and cooling cost. Add a utility rebate if you have one. Check that the thermostat works with your system before you buy; most need a C wire, and an electrician or HVAC tech can add one if yours doesn't have it.
How this is calculated
Cost is the thermostat's price plus installation, minus any rebate. Annual savings is your heating and cooling bill times ENERGY STAR's minimum certified savings: 8% for heating and 10% for cooling, so 9% for a bill that's about even. Payback is net cost divided by annual savings.
Where the savings figures come from
To be ENERGY STAR certified, a smart thermostat has to show, from a year of real data in hundreds of customers' homes, that it cuts heating run time by at least 8% and cooling run time by at least 10% nationally. These are minimums at a 95% confidence level, so the calculator's estimate is on the conservative side. Manufacturers claim more; ecobee, for example, advertises savings of up to 26%.
Example
A basic $130–$140 smart thermostat you install yourself, with a $900 heating and cooling bill split about evenly, saves about $81 a year and pays back in roughly 1.6–1.7 years. A premium thermostat with professional installation ($360–$480) pays back in about 4.4–5.9 years.
Estimate only. Thermostat prices are manufacturer list prices as of October 2026 and installation figures are published national ranges. You'll save less if you already program setbacks on your current thermostat, and more if you leave it at one temperature.
Read the full guide
Do Smart Thermostats Save Money? Cost, Savings, and Payback