Draw the network before calculating
Make one row per powered device with its role, measurement and operating hours. Identify whether the main mesh unit replaces the old router or runs alongside it. Keeping both powered changes the comparison, even if the old router’s wireless function has been disabled.
Include a separate switch or backhaul equipment where present. A product’s “two-pack” price describes the purchase bundle, not the number of devices your final installation necessarily needs.
Calculate the added nodes
Assume two added nodes each average 6 W and run continuously. Their combined 12 W uses 0.012 × 8,760 = 105.12 kWh per 365-day year. At $0.18/kWh, the annual cost is $18.9216, or about $18.92.
For a 30-day month, the same assumption produces 8.64 kWh and about $1.56. Neither figure includes the primary router or modem, and neither is a specification for a real mesh product.
Compare complete replacement setups
Suppose a new three-node system replaces an old router plus two extenders. Subtract the old system’s measured annual use from the new system’s estimated annual use. Calling all three new nodes “extra” would overstate the increase.
Conversely, counting only the main node would miss two continuously powered devices. Keep the comparison boundary consistent and distinguish measured values from manufacturer data or assumptions.
Use coverage to decide what stays
Before buying more hardware, check placement and the manufacturer’s setup guidance within your apartment’s constraints. Evaluate the rooms where you actually need reliable service. Removing a node that eliminates dead zones may save little electricity while making the network frustrating. If you test a smaller arrangement, confirm the required coverage first and then compare energy. Retain a device inventory with your estimate so future additions or replacements are easy to update.
Choose your next step
Continue with the question that matches your next decision:
Sources & further reading
Numerical examples are illustrative unless explicitly described as measured. This guide does not claim hands-on product testing. Read the methodology and editorial disclosure.