Cost to Run an Electric Water Heater (4500 W)
A 4500 W electric water heater running 3 hours daily for 30 days at $0.15/kWh costs approximately $60.75 per month.
How to use this tool
- Read the appliance's wattage from its label or spec sheet.
- Estimate how many hours per day it actually runs.
- Enter the number of days to total (30 for a month, 365 for a year).
- Enter your electricity rate in dollars per kWh.
- Read the energy used in kWh and the running cost.
Electric water heaters account for 14–18% of a home's energy use — calculate your actual monthly heating cost with this tool.
Frequently asked questions
- How do I find an appliance's wattage?
- Look for a watts (W) rating on the label, manual, or spec sheet. If it lists amps (A) and volts (V) instead, multiply them: watts = amps × volts. A plug-in power meter gives the most accurate real-world figure.
- Why does my fridge cost less than this says?
- Refrigerators and air conditioners cycle their compressors on and off, so they don't draw full wattage 24/7. Use the compressor's actual run-time hours, or a measured average wattage, rather than nameplate watts times 24.
- What uses the most electricity at home?
- Heating and cooling, water heating, and electric clothes drying are typically the biggest loads, followed by refrigeration and always-on electronics. High-wattage devices used for many hours dominate the bill.