Enter a device's wattage, how many hours a day it runs, and your rate per kWh to see the real cost.
Based on the device's rated wattage — actual draw can vary, especially for compressors and motors with startup surges.
Nameplate wattage times hours used gives kWh, and kWh times your utility rate gives dollars — the same math your utility bill uses, just applied to one device instead of the whole house. This is the fastest way to answer "is it worth unplugging this" or to estimate a solar-offset load for a specific appliance.
This is the same underlying formula your utility uses to generate your bill, just applied to a single device instead of your whole house — which makes it useful for answering specific questions like whether an old space heater or a always-on aquarium pump is worth replacing, rather than just watching a total monthly number move without knowing why.
Check the nameplate or spec sheet — most list watts directly, or amps and voltage which you can run through our Amps to Watts calculator.
Many devices — fridges, AC units, water heaters — cycle on and off rather than running continuously at rated wattage, so real-world usage is usually lower than a naive full-time estimate.
Not directly — enter your effective rate for the time period the device typically runs, and if you're on a tiered or time-of-use plan, use the rate that applies to when you actually use the device for the most accurate estimate.