Calculate how much energy any appliance uses and what it costs to run. Enter wattage, hours of daily use, and your electricity rate.
Every electrical appliance in your home has a wattage rating that tells you how much power it draws when running. Multiply that wattage by the number of hours you use it, and you get energy consumption in watt-hours. Divide by 1,000 to convert to kilowatt-hours (kWh), the unit your utility uses for billing. This calculator does all of that automatically.
From a 1,500-watt space heater to a 10-watt LED bulb, each device contributes to your electricity bill. The biggest household energy consumers are typically HVAC systems, water heaters, clothes dryers, and ovens. Understanding per-appliance cost helps you prioritize upgrades and change habits where they matter most.
This tool calculates daily, monthly, and annual energy use and cost for any single appliance. Use it to audit your entire home by calculating each device one at a time, then rank them by cost to find the biggest savings opportunities.
This measurement provides a critical foundation for energy auditing and sustainability reporting, helping organizations meet regulatory requirements and voluntary environmental commitments.
Knowing which appliances cost the most to run empowers you to make smarter choices. You might discover your old refrigerator costs $200/year while a new ENERGY STAR model would cost only $50/year. This calculator turns wattage labels into real dollar costs. Having accurate metrics readily available streamlines utility bill analysis, budget forecasting, and investment planning for energy efficiency projects and renewable energy installations.
kWh = Watts × Hours per Day × Days / 1,000 Cost = kWh × Rate ($/kWh)
Result: $23.40/month
A 1,500-watt space heater used 4 hours per day for 30 days consumes 1,500 × 4 × 30 / 1,000 = 180 kWh per month. At $0.13/kWh, that costs 180 × $0.13 = $23.40 per month.
Refrigerators typically draw 100–400 watts average (with compressor cycling). Clothes dryers use 2,000–5,000 watts. Central air conditioning systems consume 2,000–5,000 watts. A microwave uses 600–1,200 watts. Knowing these ranges helps you estimate costs even without checking exact labels.
List every electrical device in your home with its wattage and estimated daily hours. Run each through this calculator, then sort by monthly cost. You'll likely find that just 5–10 appliances account for 80% of your electricity bill. Focus efficiency upgrades on those devices first.
Small devices add up. A cable box drawing 30 watts 24/7 costs about $35/year. A desktop computer on standby at 50 watts costs $57/year. Multiply these phantom loads across a dozen devices, and you're spending $200–$400/year on electricity for things you're not even using.
Look for a label on the back or bottom of the appliance showing watts (W) or amps and volts. If only amps are listed, multiply amps by voltage (usually 120V in the US) to get approximate watts. The manual or EnergyGuide sticker also lists this information.
HVAC systems (heating and cooling) typically account for 40–50% of home electricity use. Water heaters, clothes dryers, ovens, and refrigerators are the next largest consumers. Lighting and electronics make up the remainder.
It provides a good estimate for appliances that run at constant power. For devices that cycle (like refrigerators or HVAC compressors), the actual consumption depends on the duty cycle. Using average wattage rather than peak wattage improves accuracy.
Watts (W) measure instantaneous power draw. Kilowatt-hours (kWh) measure total energy consumed over time. A 1,000-watt device running for 1 hour uses 1 kWh. Your electricity bill is based on kWh, not watts.
Yes, many appliances draw standby power (phantom load) even when off. TVs, game consoles, and chargers are common culprits. Use power strips to easily cut power to groups of devices and save 5–10% on your electricity bill.
The formula is the same — use the wattage listed on the appliance. Dryers, ovens, and water heaters are 240V but their wattage already accounts for the higher voltage. Just enter the wattage and hours of use.