Electrical Load Calculator
| Appliance | Watts | Hrs/Day | kWh/Day |
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Calculate Your Home's Electricity Usage and Cost
Most households have no idea how much each appliance costs to run — until the electricity bill arrives. This calculator lets you see your daily, monthly, and annual kWh usage and costs for every appliance in your home, all at once. The donut chart shows which appliances are eating the most of your budget, making it easy to identify where changes would have the biggest impact.
How to Use This Calculator
Edit any appliance name, wattage, or hours per day in the table — the calculator updates automatically. Enter your actual electricity rate (from your utility bill, usually in cents per kWh) for accurate cost estimates. The US national average is about $0.13/kWh, but rates range from $0.08 in Louisiana to over $0.30 in Hawaii and California.
How kWh Is Calculated
A 1,500 W space heater running 8 hours per day: 1,500 × 8 ÷ 1,000 = 12 kWh/day. At $0.13/kWh, that's $1.56/day, $46.80/month, or $569/year — just for one heater.
Typical Appliance Wattages
- Refrigerator: 100–200 W (runs ~24 hrs but cycles — effective ~8 hrs/day)
- Central AC (3 ton): 3,000–3,500 W
- Electric water heater: 4,000–5,500 W (active ~3–4 hrs/day)
- Electric dryer: 5,000–6,000 W per cycle (~1 hr)
- Desktop computer: 150–300 W (gaming PCs: 400–700 W)
- LED TV (55"): 60–120 W
- LED light bulb: 8–15 W
- Microwave: 900–1,200 W (active use only)
Where Your Energy Bill Is Really Going
Heating and cooling account for 40–50% of a typical home electricity bill. Water heating adds another 14–18%. Everything else — lighting, appliances, electronics — makes up the remaining third. This is why HVAC upgrades, better insulation, and smart thermostat use have a disproportionately large impact compared to turning off lights.
Frequently Asked Questions
How do I find the wattage of my appliances?
Check the nameplate on the back or bottom of the appliance — it shows voltage, amps, and often watts directly. If it shows volts and amps but not watts: Watts = Volts × Amps. For devices that vary in output (dimmer switches, variable-speed motors), the nameplate shows maximum draw. A kill-a-watt meter plugged between the device and outlet gives you an exact real-world measurement over any time period.
What's the average US monthly electricity bill?
According to the EIA, the average US residential bill is around $115–$130/month, consuming roughly 900 kWh. This varies significantly by region — the Southeast uses much more due to air conditioning demand — and by household size. At $0.13/kWh: 900 kWh × $0.13 = $117/month. Hawaii and California users often pay $200–$300+ per month.
How much does it cost to run an EV at home?
An average EV uses 3–4 miles per kWh. At 1,000 miles/month that's 250–333 kWh, or $33–$43/month at $0.13/kWh. Compare to a 30 MPG gas car at 1,000 miles: ~33 gallons × $3.50 = $116/month. Home charging is generally much cheaper than gas, especially with time-of-use rates for overnight charging when electricity prices are lowest.
Does phantom load (standby power) really matter?
Yes — the DOE estimates always-on devices account for 5–10% of home energy use. Common culprits: cable boxes (17 W), game consoles in instant-on mode, older TVs in standby. At 200 W of constant phantom load: 200 × 24 ÷ 1,000 × 365 × $0.13 = $228/year. Smart power strips that cut standby power to entertainment centers pay for themselves quickly.
What changes make the biggest dent in my electricity bill?
In order of typical impact: (1) Smart thermostat — 10–15% HVAC savings; (2) LED lighting if you still have incandescent bulbs — 75% reduction in lighting load; (3) Sealing air leaks and improving insulation — reduces HVAC runtime significantly; (4) Low-flow showerhead with electric water heater — reduces water heating load; (5) ENERGY STAR appliances when replacing — 20–50% less than older models.