kWh Usage and Cost Converter
Convert watts and hours into kWh and dollars.
Result
CO2 (US avg grid)
114.8 lbs
Cost per day
$0.77
Total cost
$22.95
Energy used
135.0 kWh
Formula
Calculation logicFrequently asked questions
How do I convert watts to kWh?
Multiply watts by hours, then divide by 1,000. A 100W bulb for 10 hours uses 1 kWh.
What is the difference between kW and kWh?
kW is power at an instant; kWh is energy over time. Bills charge kWh, demand charges price peak kW.
How do I read kWh from my meter?
Subtract last month's reading from this month's. Smart meters show the same number under usage history.
How much does 1 kWh cost?
Roughly 13 to 33 cents depending on state. Multiply your kWh by your rate for the energy portion.
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