electronics · 10W typical
Running a cable/dsl modem costs about $1.19/month.
That's the typical cable/dsl modem at 10W, 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 cable/dsl modem can cost very different amounts depending on usage patterns. Three common scenarios, at the US-average rate.
always-on
$1.19
per month
needed 24/7 for internet
Where you live
$2.15 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¢ | $2.97 | $36.09 |
| California | 31.4¢ | $2.26 | $27.51 |
| Massachusetts | 30.8¢ | $2.22 | $26.98 |
| Connecticut | 28.7¢ | $2.07 | $25.14 |
| Rhode Island | 27.9¢ | $2.01 | $24.44 |
| New Hampshire | 24.6¢ | $1.77 | $21.55 |
| Alaska | 24.3¢ | $1.75 | $21.29 |
| New York | 22.3¢ | $1.61 | $19.53 |
| Maine | 22.1¢ | $1.59 | $19.36 |
| Vermont | 21.5¢ | $1.55 | $18.83 |
| Michigan | 19.3¢ | $1.39 | $16.91 |
| New Jersey | 19.1¢ | $1.38 | $16.73 |
| Maryland | 18.4¢ | $1.32 | $16.12 |
| Pennsylvania | 18.1¢ | $1.30 | $15.86 |
| District of Columbia | 17.8¢ | $1.28 | $15.59 |
| Wisconsin | 17.4¢ | $1.25 | $15.24 |
| Delaware | 17.2¢ | $1.24 | $15.07 |
| Illinois | 16.9¢ | $1.22 | $14.80 |
| Ohio | 16.6¢ | $1.20 | $14.54 |
| Nevada | 16.3¢ | $1.17 | $14.28 |
| Indiana | 15.8¢ | $1.14 | $13.84 |
| Virginia | 15.7¢ | $1.13 | $13.75 |
| Minnesota | 15.6¢ | $1.12 | $13.67 |
| Colorado | 15.4¢ | $1.11 | $13.49 |
| Alabama | 15.2¢ | $1.09 | $13.32 |
| West Virginia | 15.2¢ | $1.09 | $13.32 |
| Florida | 15.1¢ | $1.09 | $13.23 |
| New Mexico | 14.8¢ | $1.07 | $12.96 |
| Texas | 14.8¢ | $1.07 | $12.96 |
| Arizona | 14.7¢ | $1.06 | $12.88 |
| South Carolina | 14.7¢ | $1.06 | $12.88 |
| Kansas | 14.6¢ | $1.05 | $12.79 |
| Georgia | 14.2¢ | $1.02 | $12.44 |
| Iowa | 14.1¢ | $1.02 | $12.35 |
| North Carolina | 13.9¢ | $1.00 | $12.18 |
| Missouri | 13.6¢ | $0.98 | $11.91 |
| Oregon | 13.4¢ | $0.96 | $11.74 |
| Tennessee | 13.3¢ | $0.96 | $11.65 |
| Kentucky | 13.2¢ | $0.95 | $11.56 |
| Mississippi | 13.1¢ | $0.94 | $11.48 |
| Oklahoma | 13.1¢ | $0.94 | $11.48 |
| South Dakota | 12.7¢ | $0.91 | $11.13 |
| Montana | 12.4¢ | $0.89 | $10.86 |
| Nebraska | 12.2¢ | $0.88 | $10.69 |
| Arkansas | 12.1¢ | $0.87 | $10.60 |
| Washington | 12.1¢ | $0.87 | $10.60 |
| Louisiana | 11.9¢ | $0.86 | $10.42 |
| Wyoming | 11.6¢ | $0.84 | $10.16 |
| North Dakota | 11.5¢ | $0.83 | $10.07 |
| Utah | 11.4¢ | $0.82 | $9.99 |
| Idaho | 11.3¢ | $0.81 | $9.90 |
Efficient vs. inefficient
A $21.68/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
10W
$1.19 per month
$14.45 per year
High draw
20W
$2.38 per month
$28.91 per year
When it hits hardest
year-round peak
24/7 always-on.
Ways to cut the cost
- 1
Buy your own modem rather than renting — ISP rentals often older/less efficient
Saves both rental fees and electricity
- 2
Combine modem+router into one unit if possible
Saves 8-12W of the second device
- 3
Upgrade old modems — newer DOCSIS 3.1 units are 30-50% more efficient
Saves 20-40 kWh/year
Real-world wattages
Pulled from actual spec sheets.
| Brand | Model | Watts |
|---|---|---|
| Arris | SURFboard SB8200 | 11W |
| Netgear | CM1000 | 11W |
| Motorola | MB8600 | 9W |
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.energy.gov · www.energystar.gov
Last updated: 2026-04-13