# Thermostat setback savings calculator: what a 7 to 10 F setback or an ENERGY STAR smart thermostat saves a year, from DOE's 10% rule and ENERGY STAR's 8% average

> DOE: as much as 10% a year by setting back 7-10 F for 8 hours a day; ENERGY STAR smart thermostat average 8%. On $1,600 of heating and cooling: $160 or $128.

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| Source | https://ownerspec.com/air/calculators/thermostat-setback-savings-calculator/ |
| Publisher | OwnerSpec (https://ownerspec.com/) |
| Published | 2026-10-03 |
| Updated | 2026-10-03 |
| Facts verified | 2026-10-03 |
| Disclosure | Contains affiliate links. OwnerSpec may earn a commission at no cost to the reader. |

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## Short answer

A thermostat setback saves a share of the annual heating and cooling bill, and the share
comes from three primary documents, each a published rule of thumb rather than a guarantee.
DOE's Home Upgrades page says you can save as much as 10% a year on heating and cooling by
turning your thermostat back 7°-10°F for 8 hours a day. A DOE Building America case study of
hydronic homes in Ithaca, New York prints about 1% heating savings for every 1°F of an 8-hour
nighttime setback. ENERGY STAR's technical bulletin says the average home with a certified
smart thermostat saves 8% on heating and cooling costs, or $50 per year. Worked example:
$1,200 of heating plus $400 of cooling is $1,600 a year. The DOE setback rule gives up to
$160; a 7°F setback at 1% per degree gives $84 on the heating bill alone; the ENERGY STAR
certified smart thermostat average gives $128. The three are alternative estimates, not a
sum.

## Fact sheet

- **Answer:** DOE's Home Upgrades page says you can save as much as 10% a year on heating and cooling by turning the thermostat back 7-10 F for 8 hours a day; ENERGY STAR's technical bulletin says the average home with a certified smart thermostat saves 8% on heating and cooling costs, or  per year. On ,200 heating plus  cooling, those rules give  and  a year.
- **Formula:** `Setback saving ($/yr) = (annual heating cost + annual cooling cost) x 10%, valid for a 7-10 F setback held 8 hours a day (DOE); per-degree saving ($/yr) = annual heating cost x setback degrees x 1%, for an 8-hour nighttime setback (DOE Building America hydronic case study); certified smart thermostat saving ($/yr) = (heating + cooling) x 8% (ENERGY STAR average)`
- **Inputs:** Annual heating cost: ,200 (typed from the reader's bills); Annual cooling cost: ; Setback: 7 F; Hours per day at the setback: 8
- **Output:** DOE setback rule: up to  a year; 1% per degree on the heating bill:  at 7 F,  at 10 F; ENERGY STAR certified smart thermostat average: . The three are alternative estimates of the same saving, not a sum.
- **Assumptions:** Every rule on the page is a published rule of thumb; the pages that print them use 'as much as', 'approximately' and 'average', and this page keeps those words; No primary source scales savings for a setback held fewer than 8 hours a day, so the calculator shows no setback figure below 8 hours rather than invent one; The 1% per degree rule comes from a Building America case study of condensing-boiler hydronic homes in Ithaca, New York (climate zones 4-7), so it is applied to the heating bill only; ENERGY STAR's 8% is a field-data average across homes; the same bulletin's  a year is the dollar average, and a home's own result depends on its bills, climate and how the features are used
- **Method:** The calculator multiplies the reader's heating and cooling costs by the three published percentages and prints each with its source and scope. The DOE, Building America and ENERGY STAR sentences were read on 2026-10-03 and are quoted as printed; nothing was metered and no home was monitored for this page.
- **Primary source:** [DOE, Home Upgrades: save as much as 10% a year on heating and cooling by turning your thermostat back 7-10 F for 8 hours a day](https://www.energy.gov/save/home-upgrades) (government or regulatory source)
- **Facts verified:** 2026-10-03
- **Last updated:** 2026-10-03
- **Canonical URL (cite this):** https://ownerspec.com/air/calculators/thermostat-setback-savings-calculator/

Buy the schedule before you buy the thermostat: the 10% in DOE's sentence comes from the setback, not the Wi-Fi, and the thermostat already on your wall can probably hold one.

> Interactive calculator, "Thermostat setback savings per year": use it on the HTML page at the URL above; the formula, constants and sources are written out below.

## What is the formula?

A **setback** is the number of degrees the thermostat is lowered (in heating season) or raised (in cooling season) from its normal setting for part of the day. A **certified smart thermostat** is, in ENERGY STAR's words, a Wi-Fi enabled device that automatically adjusts heating and cooling temperature settings, independently certified from actual field data.

| Rule | Formula | Printed by | Stated scope |
| --- | --- | --- | --- |
| DOE setback rule | (heating + cooling) x 10% | DOE, Home Upgrades: "save as much as 10% a year on heating and cooling by simply turning your thermostat back 7°-10°F for 8 hours a day from its normal setting" | 7-10 °F, 8 hours a day, "as much as" |
| 1% per degree | heating x degrees x 1% | DOE Building America, Hydronic Systems: Designing for Setback Operation: "For an 8-hour nighttime setback period, every 1°F setback will result in ≈1% savings in energy consumption" | condensing-boiler hydronic homes, Ithaca NY, climate zones 4-7, nighttime |
| ENERGY STAR smart average | (heating + cooling) x 8% | ENERGY STAR Technical Bulletin: "the average home saves 8% on heating and cooling costs, or $50 per year" | field-data average across certified models |

Each percentage is applied to the dollars on your own bills, so the calculator needs no rate or kWh. The hours input only checks whether the 8-hour condition in the first two rules is met: no source on this page prints a figure for a shorter setback, so the calculator shows none.

## What does a worked example look like?

A house that spends $1,200 a year on heating and $400 on cooling, setting back 7 °F for 8 hours each night.

1. Total heating and cooling: $1,200 + $400 = $1,600.
2. DOE setback rule: $1,600 x 10% = up to $160 a year.
3. 1% per degree, heating only: $1,200 x 7 x 1% = $84 a year. At a 10 °F setback it is $120.
4. ENERGY STAR certified smart thermostat average: $1,600 x 8% = $128 a year.

The gap between $84 and $160 is the spread between two rules of thumb, not a measurement error. The Building America figure is heating only and from boiler homes; the DOE sentence covers heating and cooling and says "as much as". Your house lands somewhere in that band, or outside it.

## Which rule applies to your house?

| Your situation | Use | Why |
| --- | --- | --- |
| Furnace or air conditioner, someone home to set it back | DOE setback rule | DOE's sentence covers heating and cooling at 7-10 °F for 8 hours; a schedule on any thermostat does it |
| Nobody will hold the schedule by hand | ENERGY STAR smart average | ENERGY STAR's 8% is measured on homes with a certified smart thermostat doing the setback automatically |
| Hot-water baseboard or boiler heat | 1% per degree, heating only | The Building America rule was measured on hydronic homes; the same sheet says a right-sized boiler may struggle to recover from a deep setback |
| Heat pump | None of the three without checking the manual | DOE's Home Upgrades page says programmable thermostats have generally not been recommended for heat pump systems, though some models are now made for them |
| Radiant floor, non-modulating boiler, or insulation well above the 2009 IECC | None: run constant | The Building America sheet lists these as homes that should not use setback |

ENERGY STAR's Heat and Cool Efficiently page gives the high end: homes with high heating and cooling bills, or unoccupied much of the day, can save approximately $100 a year with a certified smart thermostat. Its ask-the-experts page puts the average US household's heating and cooling spend at more than $900 a year.

The [smart thermostat review](/air/reviews/best-smart-thermostat/) compares the certified models on their published features. The [smart thermostat C-wire compatibility guide](/air/guides/smart-thermostat-c-wire-compatibility/) covers the common wire that Amazon's own thermostat listing says is required, and is the page to read before buying any of them.

## Where do the numbers come from?

The 10% sentence is on DOE's Home Upgrades page, read on 2026-10-03; DOE's older Energy Saver thermostats pages returned "Page not found" the same day, so this page cites the location that still prints it. DOE's Office of Indian Energy article prints the same 7-10 degrees for 8 hours a day, but as "as much as 10% per year off your heating bills".

The 1% per degree rule is the Building America case study on hydronic setback, which also prints that colder weather gives greater savings and that nighttime setback generally saves more than daytime. It is a boiler study of homes tested in 2012 to 2013, which is why the calculator applies it to heating only.

ENERGY STAR's 8% is in its technical bulletin on certified smart thermostats and its specification news release ("more than 8%", approximately $50 annually). Related sizing on this site: the [space heater running cost calculator](/air/calculators/space-heater-running-cost-calculator/) prices the room heater that often replaces a whole-house setback.

**Run the numbers before the cart**

If the ENERGY STAR line above is under the price on the live card, keep your current thermostat and program a 7-10 °F setback for 8 hours a day; that is DOE's whole sentence. If nobody will hold that schedule, the Amazon Smart Thermostat is the cheapest way to automate it and needs a C-wire, and the ecobee Smart Thermostat Essential adds occupancy-based setback. Skip the ecobee Premium unless a second room's temperature is the problem: its extra sensor changes comfort, not the 8%.

## The picks

- **Amazon Smart Thermostat**: The cheapest way to hold a schedule, if you have a C-wire (Amazon's listing says C-wire required; schedules and away settings through the Alexa app; not an ENERGY STAR certified model as far as this page checked) Amazon: https://www.amazon.com/dp/B08J4C8871/?tag=ownerspec-20
- **ecobee Smart Thermostat Essential**: The mid-range pick for a household with a $1,000+ bill (Wi-Fi scheduling with occupancy-based setback; the Amazon listing titles it ENERGY STAR certified, which this page did not confirm on energystar.gov) Amazon: https://www.amazon.com/dp/B0DT9MC2Z9/?tag=ownerspec-20
- **ecobee Smart Thermostat Premium**: Only if the calculator's answer is large enough to pay for the extra sensor (Ships with a remote SmartSensor for a second room; same scheduling and setback features as the Essential, so the calculator's savings figure is the same) Amazon: https://www.amazon.com/dp/B09XXS48P8/?tag=ownerspec-20

## Frequently asked questions

### How much does turning the thermostat down 1 degree save?

A DOE Building America case study of hydronic homes in Ithaca, New York prints the rule: for an 8-hour nighttime setback period, every 1 F setback results in about 1% savings in energy consumption. It is a heating figure from boiler homes in climate zones 4 to 7, so apply it to the heating bill, not the whole year's energy.

### Does a smart thermostat save more than a programmable one on a schedule?

The two published rules point the same way. DOE's setback sentence (as much as 10% a year at 7-10 F for 8 hours) describes the schedule, whatever holds it. ENERGY STAR's certified smart thermostat average is 8% of heating and cooling costs, from field data. The smart unit earns its price when nobody in the house will hold a schedule by hand.

### What does ENERGY STAR say a certified smart thermostat saves in dollars?

ENERGY STAR's technical bulletin says the average home saves 8% on heating and cooling costs, or $50 per year, based on actual field data. Its Heat and Cool Efficiently page adds that homes with high heating and cooling bills, or homes unoccupied for much of the day, can save approximately $100 a year with a certified smart thermostat.

### Who should not set the thermostat back at night?

The Building America case study lists hydronic homes that should run at a constant temperature instead: a boiler that cannot modulate its output, insulation significantly better than the 2009 IECC, or radiant floor or radiant panel emitters. DOE's Home Upgrades page also says programmable thermostats have generally not been recommended for heat pump systems, though some now sell models made for heat pumps.

### Can I add the setback saving and the smart thermostat saving together?

No. A smart thermostat saves by holding a setback schedule, so ENERGY STAR's 8% average and DOE's 10% setback sentence describe the same saving measured two ways, and no source on this page says they add. The calculator prints them as alternative estimates: on $1,600 of heating and cooling that is $128 against $160, and the house gets one of them.


## Sources

- [DOE, Home Upgrades: save as much as 10% a year on heating and cooling by turning your thermostat back 7-10 F for 8 hours a day; programmable thermostats and heat pumps](https://www.energy.gov/save/home-upgrades) (government or regulatory source)
- [DOE Office of Indian Energy, Six Simple Steps To Save Energy and Money This Winter: set the thermostat lower by 7-10 degrees for 8 hours a day while away or asleep, as much as 10% per year off heating bills](https://www.energy.gov/indianenergy/articles/six-simple-steps-save-energy-and-money-winter) (government or regulatory source)
- [DOE Building America case study, Hydronic Systems: Designing for Setback Operation (PDF): for an 8-hour nighttime setback every 1 F setback results in about 1% savings; who should not use setback; Ithaca NY, climate zones 4-7](https://www.energy.gov/sites/prod/files/2014/06/f16/ba_case_study_hydronic_setback.pdf) (government or regulatory source)
- [ENERGY STAR, Technical Bulletin: ENERGY STAR Certified Smart Thermostats (PDF): the average home saves 8% on heating and cooling costs, or $50 per year, based on actual field data](https://www.energystar.gov/sites/default/files/asset/document/Technical_Bulletin_ENERGY_STAR_Smart_Thermostats_508.pdf) (government or regulatory source)
- [ENERGY STAR news release, first-ever smart thermostat specification: the average consumer will save more than 8% of heating and cooling energy, approximately $50 annually](https://www.energystar.gov/about/newsroom/news-release-archive/energy-star-ends-thermostat-wars-introducing-first-ever-smart-thermostat-specification) (government or regulatory source)
- [ENERGY STAR, Heat and Cool Efficiently: homes with high bills or unoccupied much of the day can save approximately $100 a year with a certified smart thermostat](https://www.energystar.gov/saveathome/heating-cooling) (government or regulatory source)
- [ENERGY STAR, How to Choose a Smart Thermostat: the average household spends more than $900 a year on heating and cooling; savings depend on climate and use](https://www.energystar.gov/products/ask-the-experts/how-choose-smart-thermostat) (government or regulatory source)

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