ENERGY
kWh Calculator
Convert power & time to energy — with cost and carbon insights
1 kWh = 1000 Wh
E = P × t
Power & time
W
hr
$/kWh
Energy (kWh)
—
kWh
Energy (Wh)
—
Wh
Energy (Joules)
—
J
Energy (calories)
—
cal
Estimated cost
—
$
CO₂ emissions
—
kg
E (kWh) = P (kW) × t (h)
Energy comparison
Your usage compared to typical appliances
Quick facts
- 1 kWh = 1000 Wh = 3,600,000 J
- 1 kWh ≈ 0.45 kg CO₂ (US average)
- Average US residential price: ~$0.15/kWh