Calculate the cost to run any appliance, estimate your monthly electricity bill from KWh usage, calculate EV charging cost, and compare running costs of multiple appliances — all 4 modes with appliance presets and real US electricity rates.
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Verified: US EIA Electricity Data & Standard KWh Formula
Quick presets — click to autofill:
Check appliance label or manualEnter valid wattage.
Select vehicle or enter customEnter valid battery size.
Enter battery capacity in KWhEnter valid KWh.
EV batteries last longer charged to 80%Select charge level.
Starting state of chargeEnter 0–99.
Target state of chargeEnter 1–100, greater than From.
Home charging rateEnter valid rate.
Energy lost in charger/batterySelect efficiency.
EPA range for cost-per-mileEnter valid range.
Compare the running cost of two appliances side by side:
Appliance A
Wattage of Appliance AEnter valid watts.
Daily usage hoursEnter valid hours.
Appliance B
Wattage of Appliance BEnter valid watts.
Daily usage hoursEnter valid hours.
Same rate for both appliancesEnter valid rate.
Daily Cost
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⚠️ Disclaimer: Results are estimates based on the wattage and hours you enter. Actual usage varies. Electricity rates, appliance efficiency, and usage patterns affect real costs. Check your utility bill for your actual rate.
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📚 Sources & Methodology
Electricity cost calculations are based on the following verified sources:
US EIA Electric Power Monthly (2024) — Average US residential electricity rate: $0.1327/KWh national average, state-by-state breakdown eia.gov
US DOE Alternative Fuels Data Center — EV battery specifications, charging efficiency, and cost-per-mile data afdc.energy.gov
Energy Star Program, US EPA — Appliance average wattage and annual energy consumption data energystar.gov
Complete Guide to Electricity Costs — Appliances, Bills & EV Charging
How to Calculate Electricity Cost for Any Appliance
The electricity cost formula is straightforward: Cost = Watts ÷ 1000 × Hours × Rate per KWh. First convert watts to kilowatts (divide by 1,000) because electricity is billed in kilowatt-hours. Then multiply by usage hours and your electricity rate. A 1,500-watt space heater at $0.13/KWh running 8 hours costs 1.5 × 8 × $0.13 = $1.56 per day, $10.92 per week, or $46.80 per month.
Electricity Cost Formula
KWh = Watts / 1000 x Hours UsedDaily Cost = KWh x Rate ($/KWh)Monthly Cost = KWh x Rate x 30 daysAnnual Cost = KWh x Rate x 365 daysExample: 3500W AC, 6 hrs/day, $0.14/KWh: Daily = (3500/1000) x 6 x $0.14 = $2.94/day Monthly = $2.94 x 30 = $88.20/month
Average US Electricity Rates by State (2024)
State
Avg Rate $/KWh
Avg Monthly Bill
vs. National Avg
Hawaii
$0.390
$169
+194%
Connecticut
$0.254
$178
+91%
Massachusetts
$0.245
$140
+84%
California
$0.237
$140
+79%
New York
$0.202
$125
+52%
National Average
$0.133
$137
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Texas
$0.128
$151
-4%
Florida
$0.130
$138
-2%
Louisiana
$0.099
$133
-26%
North Dakota
$0.093
$119
-30%
Washington
$0.101
$104
-24%
Appliance Running Costs — What Uses the Most Electricity
Appliance
Typical Watts
Daily Use
Monthly KWh
Monthly Cost (@$0.13)
Central AC (3 ton)
3,500W
6 hrs
630
$81.90
Electric water heater
4,500W
3 hrs
405
$52.65
Electric dryer
5,000W
1 hr
150
$19.50
Space heater
1,500W
8 hrs
360
$46.80
Electric range/oven
2,500W
1 hr
75
$9.75
Refrigerator (modern)
150W
24 hrs (cycles)
45
$5.85
Pool pump
1,500W
6 hrs
270
$35.10
LED TV (55 inch)
100W
5 hrs
15
$1.95
Desktop computer
200W
8 hrs
48
$6.24
LED light bulb
9W
5 hrs
1.35
$0.18
EV Charging Cost vs. Gasoline
The cost to charge an electric vehicle at home is typically 3–4 times cheaper per mile than gasoline. At $0.13/KWh, charging 75 KWh (a Tesla Model 3 Long Range) from empty costs about $9.75. With a 330-mile EPA range, that is $0.030 per mile. Gasoline at $3.50/gallon in a 30 MPG car costs $0.117 per mile — nearly 4 times more per mile.
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Money-saving tip: Many utilities offer time-of-use (TOU) rates where electricity is cheaper at night (often 9 PM–6 AM). Charging your EV and running dishwashers or dryers during off-peak hours can cut electricity costs by 30–50% for those loads. Check your utility's rate structure before deciding on a fixed vs TOU rate plan.
❓ Frequently Asked Questions
Cost = (Watts/1000) x Hours x Rate ($/KWh). Convert watts to kilowatts first, multiply by usage hours to get KWh, then multiply by your electricity rate. Example: 1500W heater, 6 hours, $0.14/KWh = 1.5 x 6 x $0.14 = $1.26/day. Use the Appliance Cost tab above with your actual wattage and rate.
Monthly bill = Monthly KWh x Rate + Fixed charges. Find your KWh on your utility bill statement, multiply by the per-KWh rate, add any fixed service/meter charges. Or use the Monthly Bill tab above. US average: 900 KWh x $0.13 = $117 + ~$10 fixed = $127/month. Your actual bill varies by state, season, and home size.
EV charging cost = Battery KWh x Rate / Efficiency. A 75 KWh battery at $0.13/KWh with 90% Level 2 efficiency: 75 x $0.13 / 0.90 = $10.83 for a full charge. At 300-mile range: $0.036/mile. vs gasoline at 30 MPG, $3.50/gallon = $0.117/mile. EVs cost about 70% less per mile for fuel. Use the EV Charging tab above for your specific vehicle.
The US national average residential electricity rate is approximately $0.133/KWh as of 2024 (US EIA data). Rates vary significantly: Hawaii $0.39/KWh, Connecticut $0.25, California $0.24, Texas $0.13, Louisiana $0.099. Check your utility bill for your exact rate. Commercial and industrial rates are typically lower; electric vehicle time-of-use rates can be much lower at night.
A 1,500W space heater at 8 hours/day: 1.5 KW x 8hr x 30 days = 360 KWh/month. At $0.13/KWh = $46.80/month. At $0.20/KWh (Connecticut, CA): $72/month. A 1,000W heater: $31.20/month at average rates. Space heaters are expensive for whole-room heating. Use a programmable thermostat and zone heating to reduce costs.
Central AC (3,500W) at 8 hours/day: 3.5 x 8 x 30 = 840 KWh/month x $0.13 = $109.20/month. Window unit (1,200W) at 8hr: 288 KWh = $37.44/month. Costs vary by climate and SEER rating. SEER 18 vs SEER 10 saves about 44% energy. Setting thermostat to 78°F instead of 72°F saves approximately 6% per degree on AC costs.
1 KWh = 1,000 watts used for 1 hour = 1 KW x 1 hour. Your utility meter records KWh consumed. A 100W bulb for 10 hours = 1 KWh. 10 such bulbs for 1 hour = 1 KWh. US average rate is about $0.133/KWh. Running all appliances typically consumes 750-1,200 KWh/month for an average household. Your bill = monthly KWh x rate + fixed charges.
A 9W LED replaces a 60W incandescent, saving 51W. At 5 hours/day: 51W x 5hr x 365 = 93 KWh/year saved x $0.13 = $12.09/year per bulb. A home with 30 bulbs saves $363/year switching to LED. LEDs also last 25,000+ hours vs 1,000 for incandescent, saving on replacement costs. Full payback typically under 1 year at average electricity rates.
Top strategies: (1) HVAC: set AC to 78F, heat to 68F, use programmable thermostat - saves 10-15%. (2) Water heater: set to 120F, add insulation jacket - saves $30-60/year. (3) Lighting: switch all bulbs to LED - saves $150-400/year for a typical home. (4) Standby power: unplug TVs, chargers, and electronics - saves $50-100/year. (5) Time-of-use rates: shift heavy loads (EV, washer, dryer) to off-peak hours.
Modern Energy Star refrigerators use 1.0-1.5 KWh/day = 30-45 KWh/month = $3.90-$5.85/month at $0.13/KWh. Older 1990s refrigerators use 3-4x more (90-150 KWh/month). Keeping the refrigerator full (not overfull), cleaning coils annually, and maintaining 37-40°F (3-4°C) optimizes efficiency. A mini-fridge uses 0.7-1.0 KWh/day.
Power (KW or watts) is the rate of energy use right now - like speed. Energy consumption (KWh) is the total used over time - like distance. A 2 KW device running 3 hours consumes 6 KWh. A 0.5 KW device running 12 hours also consumes 6 KWh. You are billed for KWh (energy consumed), not KW (instantaneous power). High-wattage devices are only expensive if they run for many hours.
Standby or phantom load from devices left plugged in: TV 2-10W, cable box 10-25W (always on), desktop computer 5-10W, phone charger 0.5-2W, game console 1-15W, microwave clock 3W, printer 5W. Total phantom load in a typical home: 50-100W = 1.2-2.4 KWh/day = $57-$114/year. Smart power strips cut standby power for entertainment and office equipment clusters automatically.