hvac · 3W typical
Running a smart thermostat costs about $0.36/month.
That's the typical smart thermostat at 3W, run 24 hours a day at the US-average rate of 16.5¢/kWh. Change any of those and the number moves — use the calculator below to see yours.
Estimated cost
Full-power draw for 24 hours at 16.5¢/kWh.
How you use it
Cost shifts with how long it's on.
The same smart thermostat can cost very different amounts depending on usage patterns. Three common scenarios, at the US-average rate.
always-on display
$0.36
per month
continuous power for Wi-Fi and display
Where you live
$0.65 spread between the cheapest and priciest states.
Same appliance, same hours of use, different zip code — the monthly cost varies this much.
| State | Rate | Monthly | Yearly |
|---|---|---|---|
| Hawaii | 41.2¢ | $0.89 | $10.83 |
| California | 31.4¢ | $0.68 | $8.25 |
| Massachusetts | 30.8¢ | $0.67 | $8.09 |
| Connecticut | 28.7¢ | $0.62 | $7.54 |
| Rhode Island | 27.9¢ | $0.60 | $7.33 |
| New Hampshire | 24.6¢ | $0.53 | $6.46 |
| Alaska | 24.3¢ | $0.52 | $6.39 |
| New York | 22.3¢ | $0.48 | $5.86 |
| Maine | 22.1¢ | $0.48 | $5.81 |
| Vermont | 21.5¢ | $0.46 | $5.65 |
| Michigan | 19.3¢ | $0.42 | $5.07 |
| New Jersey | 19.1¢ | $0.41 | $5.02 |
| Maryland | 18.4¢ | $0.40 | $4.84 |
| Pennsylvania | 18.1¢ | $0.39 | $4.76 |
| District of Columbia | 17.8¢ | $0.38 | $4.68 |
| Wisconsin | 17.4¢ | $0.38 | $4.57 |
| Delaware | 17.2¢ | $0.37 | $4.52 |
| Illinois | 16.9¢ | $0.37 | $4.44 |
| Ohio | 16.6¢ | $0.36 | $4.36 |
| Nevada | 16.3¢ | $0.35 | $4.28 |
| Indiana | 15.8¢ | $0.34 | $4.15 |
| Virginia | 15.7¢ | $0.34 | $4.13 |
| Minnesota | 15.6¢ | $0.34 | $4.10 |
| Colorado | 15.4¢ | $0.33 | $4.05 |
| Alabama | 15.2¢ | $0.33 | $3.99 |
| West Virginia | 15.2¢ | $0.33 | $3.99 |
| Florida | 15.1¢ | $0.33 | $3.97 |
| New Mexico | 14.8¢ | $0.32 | $3.89 |
| Texas | 14.8¢ | $0.32 | $3.89 |
| Arizona | 14.7¢ | $0.32 | $3.86 |
| South Carolina | 14.7¢ | $0.32 | $3.86 |
| Kansas | 14.6¢ | $0.32 | $3.84 |
| Georgia | 14.2¢ | $0.31 | $3.73 |
| Iowa | 14.1¢ | $0.30 | $3.71 |
| North Carolina | 13.9¢ | $0.30 | $3.65 |
| Missouri | 13.6¢ | $0.29 | $3.57 |
| Oregon | 13.4¢ | $0.29 | $3.52 |
| Tennessee | 13.3¢ | $0.29 | $3.50 |
| Kentucky | 13.2¢ | $0.29 | $3.47 |
| Mississippi | 13.1¢ | $0.28 | $3.44 |
| Oklahoma | 13.1¢ | $0.28 | $3.44 |
| South Dakota | 12.7¢ | $0.27 | $3.34 |
| Montana | 12.4¢ | $0.27 | $3.26 |
| Nebraska | 12.2¢ | $0.26 | $3.21 |
| Arkansas | 12.1¢ | $0.26 | $3.18 |
| Washington | 12.1¢ | $0.26 | $3.18 |
| Louisiana | 11.9¢ | $0.26 | $3.13 |
| Wyoming | 11.6¢ | $0.25 | $3.05 |
| North Dakota | 11.5¢ | $0.25 | $3.02 |
| Utah | 11.4¢ | $0.25 | $3.00 |
| Idaho | 11.3¢ | $0.24 | $2.97 |
Efficient vs. inefficient
A $1.45/year difference across the wattage range.
Swapping a high-draw model for an efficient one pays for itself. Here's what that looks like annually at typical usage.
Most efficient
5W
$0.59 per month
$7.23 per year
Typical
3W
$0.36 per month
$4.34 per year
High draw
6W
$0.71 per month
$8.67 per year
When it hits hardest
year-round peak
The thermostat itself draws negligibly; savings come from what it controls.
Ways to cut the cost
- 1
Enable Home/Away geofencing
Cuts HVAC runtime 10-15% via automatic setbacks
- 2
Use eco mode when sleeping (6-8°F setback)
Saves 5-10% on heating and cooling
- 3
Review monthly usage reports and adjust schedules
Most users find 3-5% additional savings after 3 months of tuning
Real-world wattages
Pulled from actual spec sheets.
| Brand | Model | Watts |
|---|---|---|
| Ecobee | Smart Thermostat Premium | 3W |
| Nest Learning Thermostat (4th gen) | 3W | |
| Honeywell | T9 RCHT9610WF | 2W |
Picks that actually move the needle
Three products worth comparing if you're thinking about upgrading or supplementing what you have.
Some links below are affiliate links. If you buy, we may earn a small commission — it never changes the price you pay, and we only recommend picks we would stand behind.
See also
Related appliances
Sources: www.energystar.gov · www.energy.gov
Last updated: 2026-04-13