Smart Thermostat Savings & Payback Calculator
ENERGY STAR says a certified smart thermostat saves the average household about 8% of heating and cooling bills. Enter your HVAC cost and the real installed price to estimate your own payback.
Change any number below — your result updates instantly, no button to click.
Your details
Results
“Never” means the entered saving is zero.
Savings minus the net upfront cost; maintenance and replacement are excluded.
Measure or improve the real-world result
These tools are relevant to the numbers above; you do not need them to use the calculator.
As an Amazon Associate we earn from qualifying purchases. We may earn a commission from links on this page, at no extra cost to you.
How it works
Yearly saving = annual heating and cooling cost × expected saving percentage. Net upfront cost = thermostat price + installation and accessories − confirmed rebate, with a minimum of zero. Payback = net upfront cost ÷ yearly saving. Ten-year net saving = 10 × yearly saving − net upfront cost. The 8% default is ENERGY STAR’s approximate average for certified smart thermostats, not a guarantee for a particular home or product.
Example smart thermostat savings by HVAC bill
These examples show yearly savings before the thermostat price, installation, accessories, or rebates.
| Annual HVAC cost | 5% saving | 8% saving | 12% saving |
|---|---|---|---|
| $500 | $25 | $40 | $60 |
| $900 | $45 | $72 | $108 |
| $1,200 | $60 | $96 | $144 |
| $1,800 | $90 | $144 | $216 |
| $2,500 | $125 | $200 | $300 |
Use the calculator above for payback after the device price, installation, accessories, and any confirmed rebate.
Worked payback example
For $900 a year of heating and cooling cost and an 8% saving, the estimate is $72 per year or $6 per month. If the thermostat costs $80, requires no paid installation, and receives no rebate, the simple payback is about 1.1 years and the 10-year net saving is $640.
That is an estimate, not a promise. A household that already uses an efficient schedule may save less, while a home that is often empty but heated or cooled continuously may have more opportunity.
Compatibility comes before payback
A low calculated payback does not make a thermostat compatible. Confirm the HVAC voltage, wire terminals, number of heating and cooling stages, heat-pump and auxiliary-heat support, and any C-wire or power-adapter requirement with the manufacturer before buying. Include required accessories and professional labor in the installed cost.
Check your utility’s rebate page before purchasing. A valid rebate reduces the net cost and can shorten payback, but programs, eligible models, service territories, and deadlines change.
Why actual savings vary
Savings depend on climate, occupancy, prior thermostat habits, setpoints, HVAC equipment, insulation, and whether energy-saving features remain enabled. The percentage applies to heating and cooling cost—not the entire electricity or gas bill. Use a conservative percentage if the home already follows an effective schedule.
Sources used for assumptions: ENERGY STAR smart thermostat savings FAQ; ENERGY STAR smart thermostat buying guidance.
Frequently asked questions
How much does a smart thermostat save?
ENERGY STAR reports approximate average savings of 8% on heating and cooling bills, or about $50 per year. Individual results vary with climate, occupancy, equipment, settings, and previous thermostat use.
How do I calculate smart thermostat payback?
Add the thermostat, installation, and accessory costs; subtract confirmed rebates; then divide that net cost by the estimated annual heating and cooling saving.
Is a programmable thermostat enough?
A programmed schedule can capture savings when it matches your routine. Smart models add features such as remote control, occupancy-based adjustments, usage information, and automatic scheduling, but those features only help when they are compatible, enabled, and used.
Should I include my whole energy bill?
No. Enter only the annual amount spent on heating and cooling. Applying an HVAC savings percentage to lighting, appliances, water heating, or other unrelated energy use would overstate savings.
Can a rebate make the thermostat pay back immediately?
Yes. If a confirmed rebate covers the thermostat and installation cost, the net upfront cost is zero and the simple payback is immediate. Verify eligibility before purchasing.
Related calculators
Heat Pump Savings Calculator
A heat pump moves heat instead of creating it directly. Enter your own annual heat demand,…
HeatingHome Insulation Savings Calculator
Insulation cuts the energy you lose through walls, roof and floors — lowering both heating…
BillsElectricity Bill Calculator & High-Bill Checker
Your bill is more than energy used — it also includes fixed charges, tax and levies. Estim…