Guide
kWh cost calculator guide
If you want to calculate electricity cost from kWh directly, this page shows the shortest method and where appliance power, runtime, and tariff fit into the estimate.
Short answer
Electricity cost is kWh multiplied by your utility rate. When you only know watts, divide by 1000 first and then apply the runtime. The calculator is useful when you want the result instantly and need day, month, or year views.