Published June 12, 2026 · 7 min read
How Much Do Smart Thermostats Actually Save?
Last Updated: 2026-07-14
Everyone claims smart thermostats save money. We wanted real numbers. Here is what the independent data actually shows.
Where the Savings Numbers Come From
We do not run our own thermostat trials, so we are not going to show you a private dataset. The honest picture comes from the organisations that measure this at scale, and it is less dramatic than most articles on this topic suggest.
ENERGY STAR, which certifies smart thermostats against submitted field data, states the average plainly: savings are approximately 8% of heating and cooling bills, or about $50 per year. That is measured against heating and cooling energy specifically — not your whole electricity bill.
Two things follow, and both matter more than any single number:
- The average is modest. If a site quotes $300 a year as a typical result, treat that as a marketing figure rather than an expectation.
- The spread is enormous. ENERGY STAR is explicit that savings vary with climate, comfort preferences, occupancy and HVAC equipment. The average household is not the interesting case — the badly configured one is.
Who Actually Saves Real Money
Households that beat the average tend to share one of these traits. It is worth checking whether you are one before spending anything.
| Situation | Why savings are larger |
|---|---|
| Heat pump running excess aux heat | Resistance strips are the most expensive way to heat a house. Correct lockout configuration is where the money is — see our aux heat guide. |
| No setbacks used today | If your thermostat never moves, automation captures savings you were not capturing at all. |
| House empty for long stretches | Occupancy-based adjustment has more hours to work with. |
| Already running a good schedule | Little to gain. You are already capturing most of the benefit manually. |
That last row is the one most buying guides leave out. If you already run a sensible schedule, a smart thermostat is a convenience purchase, not a savings one.
Across the research, the savings that do appear come from two things: occupancy-based adjustments (turning down HVAC when rooms are empty) and smarter scheduling (not heating an empty house while you're at work). The Ecobee's room sensor detected occupancy in the bedrooms vs living areas, which the Nest couldn't do without buying a separate sensor.
What Moves Your Result
ENERGY STAR’s 8% is an average. Where you land depends on:
- How big your heating and cooling bill is. 8% of a large bill is more dollars than 8% of a small one, so homes in harsh climates or with electric resistance heat see more.
- What you do today. A home with no setbacks at all has the most to gain; a home already on a sensible manual schedule has little.
- Heat pump aux heat. On a heat pump, keeping the electric backup strips from firing unnecessarily is the one thermostat feature that can move a bill substantially (see below).
- Occupancy. Sensors and away detection only save when the house is regularly empty.
Calculate Your Savings
Every home is different. Use our free Smart Thermostat ROI Calculator to plug in your energy bill, home size, and climate zone — it'll tell you exactly how much you'd save and how fast the thermostat pays for itself.
The Hidden Savings Most People Miss
The thermostat itself is only part of the picture. Three effects sit alongside it, and two of them have nothing to do with the thermostat at all:
Phantom loads. Standby power from devices that are notionally off — chargers, set-top boxes, printers — is a separate line item worth attacking on its own. A scheduled TP-Link Kasa Smart Plug handles the worst offenders. Our 4-minute phantom load audit shows how to find yours rather than guess at them.
Aux heat control. On a heat pump, features like Ecobee's "Heat Pump Balance" exist to keep resistance strips from firing unnecessarily. This is the one thermostat capability that can move a bill substantially, because aux heat is the most expensive heat in the house — which is why it dominates the table above.
Behaviour. Visible energy data changes what people do: closing blinds, adjusting before leaving, unplugging what is idle. It is real, it is well documented in the efficiency literature, and it is also the effect most likely to fade after the novelty wears off. We would not buy hardware for it alone.
Bottom Line
For the average household, a smart thermostat saves roughly 8% of heating and cooling costs — about $50 a year on ENERGY STAR's figures. On a $150-250 device that is a payback measured in years, not months, and we would rather you knew that before buying.
The purchase makes clear financial sense in narrower cases: a heat pump burning aux heat it does not need, or a home currently running no setbacks at all. Outside those, cheaper fixes come first — weatherstripping, air sealing and LED replacement all return more per dollar. Our ROI calculator will tell you which case you are in.
Want personalized recommendations?
Take our 2-minute Quick Quiz — we'll tell you exactly which thermostat (and other products) will save the most money based on your home's specific energy waste pattern. Or browse our Ecobee vs Nest comparison if you've already narrowed it down. Installing a budget Amazon unit? Check the Amazon Smart Thermostat C-wire guide first.
EcoHome Intelligence participates in the Amazon Services LLC Associates Program. Where our savings figures come from — estimates on this page are built on published ENERGY STAR, DOE and EIA figures, and your result will vary. As an Amazon Associate, we earn from qualifying purchases at no extra cost to you. Savings figures are from ENERGY STAR and DOE published data, not our own testing. Your results will vary based on climate, home size, and energy habits.
Emporia Vue 3 Energy Monitor
Installs in the electrical panel; with its circuit sensors it tracks usage breaker by breaker. No subscription.
View on Amazon
ecobee Smart Thermostat Premium
ecobee’s top model. Comes with one SmartSensor for room-level readings and has Alexa built in.
View on Amazon
ecobee Smart Thermostat Essential
Entry-level ecobee with a color touchscreen. ENERGY STAR certified; works with Alexa, Google and HomeKit.
View on AmazonFree: Home Energy Audit Checklist (PDF)
A two-page, room-by-room checklist for finding air leaks, standby power and heating and cooling waste yourself, in the order that pays back fastest. Get it now, plus new fix guides by email. Unsubscribe any time.
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Frequently Asked Questions
How much money does a smart thermostat save per month?
ENERGY STAR puts average savings at about 8% of heating and cooling costs, or roughly $50 per year. Savings vary widely with climate, occupancy and HVAC type; the largest gains go to heat pumps running unnecessary aux heat and to homes that currently use no temperature setbacks.
Do smart thermostats save money in summer?
Yes. Yes, if it raises the cooling setpoint while you are out or asleep. ENERGY STAR's average of about 8% covers heating and cooling bills together; it does not publish a separate summer figure, and we do not run our own tests.
How long does it take for a smart thermostat to pay for itself?
Divide the price by your yearly saving. At ENERGY STAR’s average of about $50 a year, a $100 thermostat pays back in about two years and a $250 one in about five. Homes with high heating and cooling bills, or no setback schedule today, recover faster, and a utility rebate shortens it further.
Do smart thermostats pay for themselves?
Usually, over a few years. At ENERGY STAR's average saving of about $50 a year, a budget model pays back in roughly two years and a premium model in about five. Check your utility for a smart thermostat rebate, which cuts the price you need to earn back.
Which smart thermostat saves the most money?
Ecobee models save the most due to room sensors that eliminate hot/cold spots. In homes with multi-room temperature variation, Ecobee saves 15-23% compared to Nest's 10-13%. Nest's advantage is learning your schedule automatically.
Do smart thermostats work in apartments?
Yes, if you have access to your thermostat. Check with your landlord first. Most portable/wifi thermostats can be reinstalled when you move. Some apartments use line-voltage heating which requires special high-voltage smart thermostats.
