Electricity Cost Calculator | Home Energy & Appliance Usage
Calculate the electricity cost of any appliance or entire home. Add multiple devices with wattage and daily hours, set your kWh rate, and get daily, monthly, and annual costs with CO₂ emissions and a ranked consumption breakdown.
US average: $0.14/kWh
Finding your rate
Check your electricity bill for kWh rate or use your utility's website.
Appliances (3)
What Is the Electricity Cost Calculator | Home Energy & Appliance Usage?
This calculator converts wattage and usage time into daily, monthly, and annual electricity costs for any combination of appliances. Add your own devices or use the built-in presets for common household appliances. A ranked breakdown shows which devices cost the most so you know exactly where to focus efficiency efforts.
- ›Multi-appliance tracking, add as many devices as you need. Each appliance shows its individual monthly cost and percentage of total consumption.
- ›Custom kWh rate, enter your actual rate from your electricity bill for accurate local pricing. Supports 7 currency symbols.
- ›CO₂ emissions estimate, annual carbon footprint based on US grid average, useful for energy audits and environmental calculations.
- ›10 built-in presets, quickly add a refrigerator, AC, TV, dryer, and more with realistic wattage and usage patterns pre-filled.
- ›Sort by cost or kWh, the breakdown table re-sorts instantly so the highest consumers are always visible at the top.
Formula
Energy Consumption
kWh/day = (Watts / 1000) × Hours per day × (Days per week / 7)
kWh/month = (Watts / 1000) × Hours per day × (Days per week / 7 × 30.44)
kWh/year = kWh/month × 12
Cost
Cost = kWh × Rate ($/kWh)
CO₂ Emissions (US grid average)
CO₂ (kg) = kWh × 0.386 kg/kWh
0.386 kg CO₂/kWh is the US EPA eGRID 2022 national average. Adjust locally.
| Appliance | Typical Wattage | Annual kWh (avg use) | Annual Cost @ $0.14 |
|---|---|---|---|
| Refrigerator | 150 W | 500–700 kWh | $70–98 |
| Central AC | 3,500 W | 1,000–2,000 kWh | $140–280 |
| Electric Water Heater | 4,000 W | 3,000–4,500 kWh | $420–630 |
| Clothes Dryer | 5,000 W | 700–900 kWh | $98–126 |
| LED TV (55") | 80 W | 100–130 kWh | $14–18 |
| Desktop Computer | 200 W | 350–500 kWh | $49–70 |
| LED Bulb (10W) | 10 W | 22–36 kWh | $3–5 |
How to Use
- 1
Enter your electricity rate per kWh from your bill (US average is $0.14/kWh).
- 2
Add each appliance with its name, wattage, hours per day, and days per week.
- 3
Use the built-in presets for quick entry of common household appliances.
- 4
Click Calculate Costs to see daily, monthly, and annual totals with CO₂ estimate.
- 5
Sort the breakdown by cost or kWh to identify your highest-consuming appliances.
- 1Set your electricity rate: Find the rate on your electricity bill (look for $/kWh or cents/kWh). The US average is $0.14/kWh but rates vary widely by state and country.
- 2Add appliances: Type the name, wattage (found on the appliance label or manual), hours used per day, and days used per week. Or click "+ Load preset" for common devices.
- 3Calculate: Click Calculate Costs to see daily, monthly, and annual totals plus a ranked breakdown by appliance.
- 4Identify your biggest consumers: Use the sorted breakdown to find which appliances cost the most. Focus efficiency improvements on the top 2–3 items.
- 5Experiment with changes: Reduce usage hours for a specific appliance and recalculate to see exact savings from that change.
Example Calculation
Example: 3-appliance home at $0.14/kWh
Refrigerator: 150W × 24h/day × 7 days = 3.6 kWh/day = 109.5 kWh/mo = $15.33/mo
Air Conditioner: 1,500W × 8h/day × 5 days = 8.57 kWh/day = 261 kWh/mo = $36.50/mo
LED TV (55"): 80W × 4h/day × 7 days = 0.32 kWh/day = 9.7 kWh/mo = $1.36/mo
Total: 380.2 kWh/mo = $53.19/mo = $638/yr
CO₂: 380.2 × 0.386 × 12 = 1,762 kg/year
Understanding Electricity Cost | Home Energy & Appliance Usage
The kWh: Your Electricity Unit Explained
A kilowatt-hour (kWh) is the standard unit for measuring electrical energy on your bill. It represents 1,000 watts of power running for one hour. A 100-watt light bulb running for 10 hours uses 1 kWh. An electric vehicle with a 75 kWh battery holds enough energy to run a standard hair dryer continuously for 625 hours.
On an electricity bill, you pay a rate per kWh plus fixed charges. The variable kWh rate is what determines the cost of running any individual appliance, and it is the figure that varies the most between utility companies and regions.
Phantom Load: The Hidden Electricity Drain
Devices that are turned off but still plugged in continue to draw power. This is called phantom load, standby power, or vampire power. The Lawrence Berkeley National Laboratory found that in the average US home, standby power accounts for 5–10% of electricity consumption, roughly $100–200 per year wasted on devices doing nothing.
- ›Televisions and set-top boxes: 10–25 W in standby.
- ›Desktop computers in sleep mode: 2–6 W.
- ›Chargers left plugged in without a device: 0.1–2 W each.
- ›Smart speakers and connected devices: 1–5 W continuously.
- ›Use smart plugs with scheduling to eliminate phantom load automatically.
Practical Ways to Reduce Your Bill
- ›Upgrade to a heat pump water heater: most efficient single change in most homes. Saves $300–500/year vs. electric resistance.
- ›Raise your AC thermostat by 2°F: reduces cooling costs by 5–10% with minimal comfort impact.
- ›Switch incandescent bulbs to LED: LEDs use 75–80% less energy and last 15–25× longer.
- ›Run the dishwasher and laundry at night: time-of-use rate plans charge less during off-peak hours (10 PM–6 AM in many utilities).
- ›Seal air leaks: HVAC costs fall by 10–30% when the building envelope is properly sealed and insulated.
Frequently Asked Questions
How do I find the wattage of my appliances?
Wattage labels appear on the bottom, back, or inside panel of most appliances.
- ›Check the appliance label or data plate (usually shows "120V 60Hz 300W" format).
- ›Consult the owner's manual or manufacturer's website.
- ›Use a smart plug with energy monitoring for real-time measurement.
- ›For cycling appliances (refrigerators, AC): the rated wattage is peak, not continuous.
What is the average US electricity rate?
US residential rates vary significantly by state:
- ›National average: ~$0.14–0.17/kWh (2024, EIA data)
- ›Lowest: Louisiana, Idaho, Arkansas (~$0.08–0.10/kWh)
- ›Highest: Hawaii, California, Connecticut (~$0.25–0.40/kWh)
- ›Find your exact rate on your monthly electricity bill or your utility's website.
Which household appliances use the most electricity?
Average US home electricity breakdown (EIA):
- ›Space heating/cooling (HVAC): 45–50% of total
- ›Water heating: 14–18%
- ›Washer/dryer: 5–7%
- ›Refrigerator: 3–5%
- ›Lighting: 5–10%
- ›Electronics (TV, computers, devices): 4–6%
Replacing an old electric resistance water heater with a heat pump water heater saves $300–500/year alone.
How is the CO₂ estimate calculated?
CO₂ = kWh × emission factor. The calculator uses the US national average of 0.386 kg CO₂/kWh.
- ›US average: 0.386 kg CO₂/kWh (EPA eGRID 2022)
- ›High-coal states (WY, KY): ~0.8–1.0 kg CO₂/kWh
- ›High-hydro/nuclear states (WA, VT): ~0.05–0.15 kg CO₂/kWh
- ›European grid average: ~0.25 kg CO₂/kWh (2023)
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