How Much Does It Cost to Run a Cable or Fiber Modem in South Dakota? (2026)
A modem runs all day at 5 to 15 watts. Combined with a separate router the pair uses around 15 to 25 watts continuously, roughly 150 to 200 kWh a year.
A typical cable or fiber modem (8 W) costs $0.001 per hour, or about $0.88 per month at 24 hours a day in South Dakota. Cheap to run
| Wattage | Per hour | Per day | Per month | Per year |
|---|---|---|---|---|
| Low 5 W | $0.001 | $0.018 | $0.55 | $6.73 |
| Typical 8 W | $0.001 | $0.029 | $0.88 | $10.76 |
| High 15 W | $0.002 | $0.055 | $1.66 | $20.18 |
Formula: watts ÷ 1000 × hours × price per kWh. Typical use is 24 h/day ≈ 70 kWh per year.
One day of a cable or fiber modem (0.19 kWh) is the same electricity as
- 3.8hours of a fridge
- 4.3hours of a laptop
- 19hours of Wi-Fi
- 21hours of an LED bulb
In South Dakota, with electricity at 15.4¢ per kWh (source: EIA Table 5.6.A, 2026-06), a typical cable or fiber modem costs $0.001 per hour and about $10.76 per year at 24 hours a day. That is about 16% less than the national average for the US ($1.06 per month), because electricity in South Dakota costs 15.4¢ per kWh against 18.3¢ nationally. Each $1.00 of electricity buys roughly 813.8 hours of use.
How to lower the cost of running a cable or fiber modem
- Replace a separate modem and router with a combined gateway to halve the draw.
- Do not turn it off at night. Reconnection delays are rarely worth the small saving.
- Retire old network gear. Older units often use double the power of current ones.
Frequently asked questions
How much electricity does a modem use per month?
Around 6 kWh a month at 8 watts continuous.
Is it worth turning off the modem at night?
It saves about 2 to 3 kWh a month. Most people find it not worth the hassle.
Do fiber ONTs use less power than cable modems?
Usually a little less, typically 5 to 8 watts.
Cost by region
US states
- Alabama
- Alaska
- Arizona
- Arkansas
- California
- Colorado
- Connecticut
- Delaware
- District of Columbia
- Florida
- Georgia
- Hawaii
- Idaho
- Illinois
- Indiana
- Iowa
- Kansas
- Kentucky
- Louisiana
- Maine
- Maryland
- Massachusetts
- Michigan
- Minnesota
- Mississippi
- Missouri
- Montana
- Nebraska
- Nevada
- New Hampshire
- New Jersey
- New Mexico
- New York
- North Carolina
- North Dakota
- Ohio
- Oklahoma
- Oregon
- Pennsylvania
- Rhode Island
- South Carolina
- South Dakota
- Tennessee
- Texas
- Utah
- Vermont
- Virginia
- Washington
- West Virginia
- Wisconsin
- Wyoming
Canadian provinces
Related appliances
- Computer Monitor30 W typical
- Printer (Inkjet or Laser)30 W typical
- Phone Charger10 W typical
- Home Server or NAS40 W typical
Use the generic electricity cost calculator · Which uses more? Take the quiz