Watts to kWh Calculator | PES Supply

Watts to kWh Calculator

Convert watts to kilowatt-hours (kWh) for energy consumption. Enter wattage and hours of use to calculate energy usage and costs.

Formula

Watts to kWh Conversion Table

Watts 1 Hour 5 Hours 24 Hours Monthly (30d)
100W 0.1 kWh 0.5 kWh 2.4 kWh 72 kWh
400W 0.4 kWh 2.0 kWh 9.6 kWh 288 kWh
1,000W 1.0 kWh 5.0 kWh 24.0 kWh 720 kWh
3,000W 3.0 kWh 15.0 kWh 72.0 kWh 2,160 kWh
5,000W 5.0 kWh 25.0 kWh 120.0 kWh 3,600 kWh
10,000W 10.0 kWh 50.0 kWh 240.0 kWh 7,200 kWh

Solar & Battery Sizing Applications

  • Calculate daily energy needs for off-grid solar systems
  • Size battery banks based on daily kWh consumption
  • Estimate generator fuel consumption by load
  • Determine solar panel array size needed
  • Calculate payback period for solar installations
How do I convert watts to kWh?

Divide watts by 1,000 to get kW, then multiply by hours of use: kWh = (Watts / 1000) x Hours. A 400W solar panel producing for 5 hours generates 2.0 kWh/day.

How many kWh does a 400W solar panel produce per day?

Assuming 5 peak sun hours: (400W / 1000) x 5 = 2.0 kWh/day, or about 60 kWh/month.

How many solar panels do I need for 30 kWh/day?

At 5 peak sun hours with 400W panels: 30,000Wh / (400W x 5h) = 15 panels. Account for 20% system losses, so plan for ~18 panels.