For one combined Wi-Fi router and modem load, the reviewed dataset gives 15 W (range 10–20 W) for running power. Its starting-power entry is also 15 W (range 10–20 W).
These are low-confidence planning values, not measurements or specifications for a particular model. They cover one combined router-plus-modem load. An optical network terminal (ONT), mesh node, separate backup supply, or other powered communications equipment is not included and must be counted separately if your connection requires it.
One router-plus-modem load and the generator check
For the registered one-load scenario, the sizing result is 19 W running, 15 W starting.
Both capacity requirements matter, but the recommended running capability is the larger requirement in this result. The calculation applies its bound planning allowance to the 15 W typical running load. That method is specific to this registered result and is not a universal generator-sizing rule.
This is a capacity check, not a generator or power-source compatibility approval. It does not verify output quality, voltage, connectors, grounding, transfer equipment, or whether a particular router, modem, ONT, or power adapter will operate correctly from a particular source. It also does not guarantee internet access because communications equipment outside your home may lose power during the same outage.
What this wattage range includes
The registered entry represents one combined Wi-Fi router and modem load. It does not provide separate values for a router, modem, combined gateway, mesh node, or ONT.
The dataset lists the same 15 W typical value and 10–20 W range for running and starting power. This means the two registered planning entries match; it does not prove that every networking product has identical running and switch-on behavior.
For an outage plan, classify each device by whether your connection needs it. A router and modem may be essential, and an ONT may also be essential for fiber service. Extra mesh nodes or backup equipment may be optional depending on your setup. Unknown wattage is not zero, so do not leave a required powered box out of the total merely because its rating is unavailable.
Running watts are not daily energy use
Watts (W) describe power—the rate at which equipment uses energy. Watt-hours (Wh) and kilowatt-hours (kWh) describe energy used over time.
For a planning estimate with steady power, the relationship is:
Energy in Wh = power in W × operating time in hours
This page does not supply operating duration, duty cycle, measured average power, or daily energy. We therefore cannot present the running-watt range as measured Wh or kWh per day. A defensible daily estimate requires both operating time and a representative or measured power value for your equipment.
How to check your own router, modem, or ONT
- Identify every powered box. Follow the communications path and list the modem, router or gateway, ONT, mesh nodes, switches, and any separate battery-backup equipment.
- Find each model number. Check the underside or back of each device and its power adapter. Manufacturer documentation may provide model-specific electrical information.
- Read adapter ratings carefully. If a DC adapter lists output voltage in volts and current in amps, multiplying V × A gives its rated DC output capability in watts. That is an adapter limit, not necessarily the device's typical wall-outlet consumption.
- Prefer a wall-power measurement when precision matters. A suitable plug-in power meter can provide a better input for equipment powered through a compatible wall plug. The reading still applies only to the operating conditions under which it was taken.
- Add missing equipment separately. No ONT wattage is supplied here. Obtain its label rating, manufacturer specification, or measured power before including it in your communications-load total.
Limits of this planning estimate
The reviewed entry carries low confidence because the exact router and modem models and their nameplate data are unknown. Use its 10–20 W range for preliminary planning, not as a model-specific promise.
This page calculates only the registered default: one combined router-plus-modem load. It does not calculate a separate ONT, multiple network devices, runtime, battery capacity, fuel use, or daily energy. The result is a planning estimate, not validated electrical dispatch or a guarantee of generator performance.
No retrieved source excerpt was supplied for independent source-level verification, so this article does not quote or cite an external source.
Next step for your outage plan
Start with the router-plus-modem range shown here, then list every additional powered device needed to keep your connection working. Separate essential equipment—potentially including an ONT—from optional equipment such as extra mesh nodes. Once you have a wattage for each required load, use the home generator calculator to size the larger essential-load set rather than relying on this one-appliance check.