Most people have no idea which appliances are quietly draining their electric bill. This calculator makes the invisible visible — enter a single appliance to see its cost, or run a whole home audit to find your top energy hogs and see how much you could save by switching to efficient alternatives.
Pro tip: A space heater running 8 hours a day can cost $40–$55 per month. Phantom power from devices left on standby adds $100–$200 to your annual bill.
Electricity rates typically rise 3–5% per year. See your projected costs.
How to Use the Electricity Cost Calculator
In Single Appliance mode, enter the wattage, daily usage hours, and days per week for any device. Use the common appliance pills for quick selection. In Whole Home Audit mode, add all your major appliances to see a ranked breakdown of which ones cost the most and where to save.
Understanding Watts, Kilowatts, and kWh
Watts measure instantaneous power draw. Kilowatts (kW) are just watts divided by 1,000. A kilowatt-hour (kWh) is one kilowatt used for one hour — this is what your utility bills. If a 1,500W space heater runs for 2 hours, it uses 3 kWh. At $0.16/kWh, that session costs $0.48.
The Biggest Energy Hogs in a Typical Home
HVAC systems (heating and cooling) typically account for 40–50% of a home’s electric bill. Water heaters come next at 14–18%. Clothes dryers, ovens, and space heaters draw significant wattage. By contrast, modern LED bulbs, phone chargers, and laptops are remarkably efficient. The audit mode ranks your appliances from most to least expensive so you can prioritize efficiency upgrades.
Phantom Power: The Silent Drain
Many devices draw power even when “off” — TVs, game consoles, cable boxes, and chargers left plugged in. This phantom load (also called vampire power or standby power) can add $100–$200 to your annual bill. Smart power strips that cut power when devices are off can eliminate most phantom drain.
LED vs. Incandescent: The Math
A 60W incandescent bulb running 5 hours a day costs about $17.50 per year. A 9W LED producing the same light costs about $2.60 per year. With 30 bulbs in a typical home, switching saves roughly $450 annually. LEDs also last 15–25 times longer, so the replacement cost savings add up too.
How to Read Your Electric Bill
Your bill shows total kWh consumed during the billing period. Divide the total charges (excluding fixed fees and taxes) by kWh to get your effective rate. Many utilities now offer time-of-use pricing where electricity costs more during peak hours (typically 2–7 PM weekdays) and less overnight. Pro subscribers can model TOU rates to find optimal usage schedules.
Looking for related tools? Try our Solar Savings Calculator to estimate how much you could save by switching to solar, or our Fuel Cost Calculator to plan your driving expenses. Explore all Everyday Math tools.