About Electricity Cost Calculator

Estimates electricity costs for any device or appliance based on wattage, daily usage hours, and your local electricity rate. Choose from 25 preset appliances organized by category (kitchen, HVAC, electronics, lighting, water heating), or enter custom wattage. Results include daily, monthly, and yearly costs plus CO₂ emission estimates based on the average US grid factor of 0.92 lbs CO₂/kWh.

• 25 appliance presets across 8 categories with typical wattage and daily usage hours
• Custom device mode accepts any wattage value
• Calculates daily, monthly (configurable days), and yearly energy consumption in kWh
• Cost projections at your local electricity rate (default $0.12/kWh US average)
• CO₂ emissions estimated at 0.92 lbs per kWh (US grid average)
• Efficiency comparison panel shows savings from reducing usage by 2 hours/day
• Calculation history with CSV export; efficiency rating from Very Efficient to Very High Consumption

Frequently Asked Questions

Where do I find my electricity rate?

Check your utility bill—look for the per-kWh charge, usually listed as the supply or generation rate. In the US, rates range from $0.08/kWh (Louisiana) to $0.30+/kWh (Hawaii, California). The default $0.12 is the national average.

How accurate are the CO₂ estimates?

They use the US national average grid emission factor. Actual emissions vary by region—areas with more hydro, nuclear, or renewables have lower factors. Check EPA’s eGRID data for your specific region if precision matters.