Data sourced from the U.S. Dept. of Energy, Energy Star, and the EIA.

What Temperature Should You Set Your Thermostat?

The thermostat settings the Department of Energy recommends for winter and summer, why the setback matters more than the number, and how much it realistically changes your bill.

By TrimWatt Editorial Teamwho we arePublished July 22, 2026Verified July 22, 20269 min readNot yet independently reviewed — how we review
Key takeaways
  • DOE suggests around 68°F in winter while awake, lower while asleep or away; in summer, as high as comfortable.
  • The setback — the gap between occupied and unoccupied temperatures — saves more than any single setpoint number.
  • Heat pumps are the exception: a large manual setback can trigger expensive backup resistance heat, so use the thermostat's smart-recovery mode instead.
  • Very humid climates, homes with radiant floors or high thermal mass, and medically vulnerable households need a different approach.
  • Consistency beats micromanagement — repeatedly overriding a schedule usually erases the benefit.
Digital thermostat display showing a 68°F heating setting on a wall in a living room.
On this page
  1. Starting points by situation
  2. Why the gap matters, and what one degree really does
  3. The heat pump exception
  4. What it's worth in dollars
  5. Cooling season, humidity and comfort
  6. Safety, and who should not set back
  7. What to do next

Most thermostat advice fixates on a single number. The number matters less than the pattern: how far you let the house drift when nobody needs it comfortable, and for how many hours a day. Below is a starting point for each situation, the arithmetic for what a schedule can change, and the cases where the usual advice stops applying.

Starting points by situation

SituationStarting pointWhyWatch for
Winter, awake and at homeAbout 68°FDOE's suggested starting point; it sets the baseline you set back fromYour own comfort — adjust from here
Winter, asleep7–10°F below your waking settingThe longest uninterrupted setback of the dayFeeling cold in bed; if so, make the setback shallower rather than abandoning it
Winter, awayThe same 7–10°F backThe widest gap between inside and outside while nobody benefitsA setting low enough to put pipes at risk in an unheated or cold-prone space
Summer, at homeAs high as you find comfortableCooling energy rises as the gap between inside and outside growsHumidity: cooling also dries the air
Summer, awayHigher still than when you are homeNarrows the gap to the outdoors while nobody is thereIn very humid homes, indoor humidity climbing while you are out
Heat pump, any seasonA shallow, thermostat-managed scheduleLarge manual swings can call in electric backup heat on recoveryBackup heat running at the end of a setback
Radiant floors or high thermal massFew, small changesThese systems respond slowly, so frequent setbacks work poorlyWaking to a cold floor that has not yet recovered
Starting points, not rules. DOE's suggested waking setting is about 68°F; the 7–10°F setback range is the one used in the worked example further down. DOE gives no single summer number, so none is invented here.

Consistency beats micromanagement. Repeatedly overriding a schedule usually erases the benefit, so pick settings you will leave alone.

Why the gap matters, and what one degree really does

Heat moves from warm to cold, and faster the bigger the difference. Letting your house sit closer to outdoor temperature while you're out means less heat escaping, so less energy to replace. That is why the setback carries the saving, not the headline number: it narrows the indoor–outdoor gap for hours at a time.

What it does not give you is a trustworthy 'percent per degree' rule. The benchmark we can tie to a source is the DOE guidance used in the first worked example below — a saving of about 10% for a 7–10°F setback sustained eight hours a day. We do not scale that down to a per-degree figure: savings depend on climate, insulation, equipment and how the house recovers, and a straight-line shortcut would be false precision.

The heat pump exception

Don't set a heat pump back like a furnace
If a heat pump has to recover several degrees quickly, many systems bring in electric resistance backup heat — the most expensive heat in the house. Use your thermostat's heat-pump mode or smart recovery instead of a deep manual setback.

What it's worth in dollars

Heating and cooling is the largest single load in most U.S. homes, so a percentage change here moves more money than anything you can unplug. The exact figure depends on your climate zone, your fuel, your insulation, and your local rate, which is why the examples below show the arithmetic with placeholders rather than a national number.

Putting a number on your own setback

StepCalculationResult
1. Annual heating + cooling spendyour annual energy bill × the share that goes to HVAC$1,200 (example)
2. Apply DOE setback guidance$1,200 × 10% (7–10°F back for 8 hours a day)≈ $120/yr
3. Convert to a monthly figure$120 ÷ 12≈ $10/month
4. Sanity-check against your billcompare to the same month last year, in kWhyour real number

The 10% figure is DOE guidance for a 7–10°F setback sustained 8 hours a day, not a measurement of your home. Swap in your own HVAC share and setback depth — the arithmetic is the point, not our example.

How a schedule changes the average indoor–outdoor gap

StepCalculationResult
1. A day's setpoints8 h asleep at 61°F · 9 h away at 61°F · 7 h awake at home at 68°F24 hours
2. Time-weighted setpoint(17 h × 61°F + 7 h × 68°F) ÷ 24 = 1,513 ÷ 24≈ 63.0°F
3. Gap if you hold 68°F all day68°F − 35°F outdoors (assumed constant)33°F
4. Gap with the schedule63.04°F − 35°F≈ 28.0°F
5. Reduction in the gap(33 − 28.04) ÷ 33≈ 15%

This is a ceiling from a first-order model, not a forecast. It assumes the house reaches 61°F the instant the schedule changes and that heat loss tracks the gap alone. Real houses cool slowly and need energy to recover, and equipment efficiency varies with the weather, so a real saving sits below it — consistent with DOE's lower 10% benchmark above. The outdoor temperature, the setpoints and the hours are all illustrative. Use it to compare schedules against each other, not to promise yourself a number.

HouseholdRealistic setback windowWhat to expect
Empty 9-5, sleeps 8h16 hours a dayLargest opportunity — two setback periods
Someone home all dayOvernight onlySmaller, but the overnight setback still counts
Shift work, irregularVaries dailyManual scheduling fails; occupancy-based control does better
Heat pump, cold climateShallow, thermostat-managedDeep manual setbacks can call in backup heat and cost more
How the same advice lands differently depending on the household. These are directional, not modelled outputs.
TrimWatt Savings Score — Adopting a consistent thermostat setback81/ 100Strong
ComponentPointsWhy
Payback speed40 / 40Pays back in under a year
Materiality of the saving9 / 15$120–249 a year
Effort to do20 / 20No purchase and no tools — a setting or behaviour change only.
Comfort impact3 / 10One minor trade-off most households tolerate (e.g. cooler while asleep, audible equipment).
Data confidence9 / 15Figures come from a primary federal source, but the result depends on climate, local rate, or existing equipment, so real outcomes vary widely.

Inputs used: ≈$0 upfront · ≈$120/yr modelled saving · ≈0.0 yr payback · difficulty 1/5 · comfort -1 · medium data confidence. These come from the assumptions stated in this guide, not from your home.

The TrimWatt Savings Score is an editorial decision-support tool based on published assumptions. It is not an engineering rating, a guarantee of savings, or a prediction for a specific home. The weights and band boundaries are our editorial choices — see the method (v1.1) and disagree with them if you like; the component scores are shown above so the parts remain useful even if you reject the total.

Cooling season, humidity and comfort

In summer the logic runs in reverse: the higher the setting, the smaller the gap to the outdoors. But cooling is also dehumidifying, and in a very humid climate a setpoint raised too far can leave air that is warm and damp, which feels worse than the number on the thermostat suggests. EPA's mold guidance includes indoor relative-humidity guidance, and our dehumidifier guide covers how to size one and what it costs to run.

Safety, and who should not set back

  • If anyone at home is medically vulnerable — an infant, an older adult, someone unwell — comfort and safety outrank the saving.
  • When the house is empty in winter, choose a setting that keeps it safe rather than the lowest the thermostat allows; unheated spaces with pipes are the risk.
  • If you wake cold, make the overnight setback shallower instead of dropping the schedule — a smaller consistent setback beats an abandoned deep one.

What to do next

Pick one setback you'll actually keep — most people start with the eight hours they're asleep — and leave it in place for a full billing cycle before judging it. If you don't want to think about it again, that's the honest case for a programmable or smart thermostat.

What these numbers assume — and where they stop

Assumptions

  • A typical single-family home with central heating and cooling on a normal daily occupancy pattern.
  • Savings scale with the size of the setback and how many hours a day it applies.
  • The second worked example uses illustrative setpoints, hours and a constant 35°F outdoor temperature. It models the indoor–outdoor gap only, not a bill.

Limitations

  • Heat pumps behave differently from furnaces: large manual setbacks can trigger backup resistance heat, which costs more than it saves. Use the thermostat's own heat-pump or 'smart recovery' mode.
  • Homes with poor insulation lose the setback benefit faster, and humidity — not temperature — often drives summer comfort.
  • Health needs come first. Do not set back aggressively where infants, elderly, or unwell people are at home.
  • There is no per-degree saving percentage here by design: the only benchmark we tie to a source is the DOE guidance on a 7–10°F setback held eight hours a day.
  • The gap-reduction figure in the second worked example is a ceiling from a simplified model. Real savings are lower because houses cool and recover gradually.

Sources

Frequently asked questions

Is 68°F really the right winter setting?

It's the Department of Energy's suggested starting point for waking hours, not a rule. What matters more is lowering it while you sleep or are out — that gap is where the saving comes from.

How many degrees should I set back?

DOE's guidance, used in our worked example, is 7–10°F below your waking setting for eight hours a day. If you wake cold or have a heat pump, make it shallower and let the thermostat manage the recovery. A smaller setback you keep beats a deep one you abandon.

How much does each degree save?

We don't give a percent-per-degree figure because we could not tie one to a source for your situation. Savings depend on climate, insulation, equipment and how long the setback lasts. The benchmark we can source is DOE's guidance on a 7–10°F setback held for eight hours a day; test it against your own bills in kWh.

Does turning the thermostat way down save more?

For a furnace, a deeper setback generally saves more. For a heat pump, a large manual setback can call in electric backup heat on recovery and cost you more, so let the thermostat manage it.

Is it cheaper to leave the heating on all day?

No. A house loses heat faster the warmer it is relative to outside, so letting it cool while you're out reduces total loss. The 'leave it on constantly' idea doesn't hold for most homes.

Run the numbers yourself