Typical wattage at a glance
Published figures vary by model, but commonly cited ranges are:
- Wi-Fi router: roughly 5 to 20 watts, with about 10 watts often used as a rough average. Newer high-performance or mesh units can sit toward the upper end.
- Modem (cable, DSL or fiber terminal): roughly 5 to 15 watts, with some higher-performance models drawing more.
- Combined modem/router gateway: often in the region of 10 to 25 watts, depending on features (see gateway vs router for what a gateway is).
- Modem plus separate router together: commonly somewhere around 10 to 35 watts.
These are estimates from general sources, not guarantees. Your equipment’s label or manual may list its rated power, but note that the label usually shows the maximum the power adapter can supply, not what the device uses day to day.
How to turn watts into cost
Electricity is billed in kilowatt-hours (kWh). The calculation is:
watts x hours / 1,000 = kWh
A device running all year is on for 8,760 hours. Using that:
| Average draw | Approximate kWh per year |
|---|---|
| 5 W | 43.8 |
| 10 W | 87.6 |
| 15 W | 131.4 |
| 20 W | 175.2 |
| 30 W | 262.8 |
Multiply the kWh by your local price per kWh to get the cost. For example, at an illustrative 15 cents per kWh, a 10-watt router would cost about 13 dollars per year, and a combined 25-watt setup about 33 dollars. Your rate will differ, so check your bill.
For hourly and daily figures: a 10-watt device uses 0.01 kWh per hour, or 0.24 kWh in 24 hours.
Does traffic change the wattage?
Usually only a little. Network equipment tends to draw most of its power just by being on, with a modest increase under heavy use. That is why uptime matters more than activity when you estimate cost.
How to measure your own equipment
The most reliable way is a plug-in electricity usage monitor (often called a watt meter or energy monitor):
- Plug the monitor into the wall outlet.
- Plug the router or modem power adapter into the monitor.
- Read the watts figure after the device has been running for a while, and note it at busy times too.
- If the monitor shows cumulative kWh, leave it for a few days for a better average.
Measure the modem and router separately, or together on a power strip, depending on what you want to know.
Would turning it off at night save much?
Switching off for about eight hours a night removes roughly a third of the yearly usage. For a 10-watt router that is on the order of 29 kWh a year, which usually amounts to a few dollars. Whether that is worth the inconvenience is a personal choice, and some devices need a constant connection. See whether you should unplug your router at night for the trade-offs, or how to set a timer on your Wi-Fi router for a gentler approach.
How big a UPS do you need?
A UPS (uninterruptible power supply) keeps equipment running briefly during a power cut. Because modems and routers use little power, even a small unit can run them for a while. To plan:
- Add up the wattage of everything you want to protect, using your measured numbers if possible.
- Check the UPS ratings. Capacity is often given in volt-amperes (VA) and watts. Your load in watts must be below the watt rating.
- Check the runtime chart from the manufacturer for your load. Runtime depends on the battery size and the load, and manufacturers publish estimates.
- Leave some headroom, since batteries lose capacity with age and your equipment may draw more than you assumed.
Some people prefer a small battery pack designed for networking gear. Check that its output voltage and connector match your device, and read the manufacturer’s compatibility notes. If you are unsure, ask the manufacturer or an electrician rather than guessing.
Heat and power
Equipment that draws more power gives off more heat, which is one reason ventilation matters. See whether a hot router can slow your internet.
Frequently asked questions
How much electricity does a Wi-Fi router use in 24 hours? At 10 watts, about 0.24 kWh. At 20 watts, about 0.48 kWh.
How much electricity does a Wi-Fi router use per hour? Equal to its wattage divided by 1,000 in kWh, so a 10-watt router uses about 0.01 kWh.
Should we turn off the Wi-Fi router at night? The saving is small. It may suit you if nothing needs the connection overnight, but it is not necessary for most homes.