Electricity Cost Calculator
Enter your electricity rate, then add appliances with wattage and daily usage. Results show monthly kWh and cost per appliance plus annual totals. Default rate is 12¢/kWh; check your electric bill for your actual rate.
| Appliance | Watts (W) | Hrs/Day | Days/Mo | kWh/Mo | Cost/Mo | |
|---|---|---|---|---|---|---|
| 108.0 | $12.96 | |||||
| 15.0 | $1.80 | |||||
| 360.0 | $43.20 | |||||
| 10.0 | $1.20 |
How to Calculate Electricity Cost
Your electricity bill is determined by how many kilowatt-hours (kWh) you consume multiplied by your utility's rate. Understanding which appliances consume the most energy helps you identify where to cut costs.
The Formula
kWh per month = Watts × Hours per Day × Days per Month ÷ 1,000 Cost per month = kWh × Rate ($/kWh)
Example: A 1,500-watt space heater used 6 hours per day for 30 days at $0.15/kWh:
kWh = 1,500 × 6 × 30 ÷ 1,000 = 270 kWh Cost = 270 × $0.15 = $40.50 per month
Typical Appliance Wattages
| Appliance | Typical Wattage | Typical Usage | Est. kWh/Month |
|---|---|---|---|
| Refrigerator (modern) | 100–200W | 24 hr/day | 72–144 kWh |
| Central A/C (3-ton) | 3,000–3,500W | 8 hr/day | 720–840 kWh |
| Window A/C unit | 500–1,500W | 8 hr/day | 120–360 kWh |
| Electric water heater | 4,000–5,000W | 3 hr/day | 360–450 kWh |
| Clothes dryer | 4,000–6,000W | 1 hr/day | 120–180 kWh |
| Dishwasher | 1,200–1,500W | 1 hr/day | 36–45 kWh |
| Washing machine | 500–1,000W | 1 hr/day | 15–30 kWh |
| LED TV (55 inch) | 50–100W | 5 hr/day | 7.5–15 kWh |
| Desktop computer | 100–300W | 8 hr/day | 24–72 kWh |
| Laptop computer | 25–60W | 8 hr/day | 6–14 kWh |
| LED light bulb (60W equiv) | 9–10W | 5 hr/day | 1.4–1.5 kWh |
| Microwave oven | 700–1,200W | 0.25 hr/day | 5–9 kWh |
| Space heater | 750–1,500W | 6 hr/day | 135–270 kWh |
| Electric oven | 2,000–5,000W | 1 hr/day | 60–150 kWh |
Electricity Rates by US State (2024–2025)
| State | Avg Rate (¢/kWh) | Annual avg bill |
|---|---|---|
| Hawaii | 38–42¢ | $2,000–$2,200 |
| Connecticut | 25–28¢ | $1,500–$1,700 |
| California | 22–26¢ | $1,100–$1,400 |
| New York | 18–22¢ | $1,100–$1,400 |
| Florida | 12–14¢ | $1,400–$1,700 |
| Texas | 10–13¢ | $1,300–$1,600 |
| Georgia | 10–12¢ | $1,300–$1,600 |
| Louisiana | 8–10¢ | $1,400–$1,700 |
| Oklahoma | 8–10¢ | $1,000–$1,200 |
| Idaho | 8–10¢ | $800–$1,000 |
Ways to Reduce Your Electricity Bill
HVAC is the priority. Heating and cooling account for 45–50% of home energy use. Setting the thermostat 7–10°F higher in summer (or lower in winter) for 8 hours per day can save up to 10% annually. Programmable or smart thermostats automate this. Sealing air leaks and adding insulation delivers permanent savings.
Switch to LED lighting. LED bulbs use 75–80% less energy than incandescent and last 15–25 times longer. The payback period for replacing all bulbs is typically under one year.
Use appliances efficiently. Run the dishwasher and washing machine only with full loads. Wash clothes in cold water — heating water accounts for about 90% of washing machine energy use. Air-dry dishes instead of using the heated drying cycle.
Unplug standby loads. Electronics in standby mode (TVs, game consoles, chargers, microwaves with clocks) collectively consume 10–20% of home electricity. Smart power strips and unplugging unused devices can yield meaningful savings.
Upgrade old appliances. A refrigerator from 2000 uses 2–3× the energy of a current ENERGY STAR model. Electric water heaters from before 2015 are typically 60–70% efficient vs. modern heat-pump water heaters at 300–350% efficiency.
Frequently Asked Questions
How do I calculate electricity cost for an appliance?
The formula is: Cost = (Watts × Hours per Day × Days per Month) ÷ 1000 × Rate per kWh. First, find the wattage on the appliance's label or manual. Multiply by daily usage hours and days per month to get watt-hours, then divide by 1,000 to convert to kilowatt-hours (kWh). Multiply by your electricity rate in dollars per kWh to get the monthly cost.
What is the average electricity rate in the US?
The US average residential electricity rate was approximately 16–17 cents per kWh in 2024–2025. However, rates vary significantly by state: Hawaii and Connecticut typically exceed 25¢/kWh, while Louisiana, Oklahoma, and Idaho average under 10¢/kWh. Check your most recent electric bill to find your exact rate — it is listed as cents per kWh or dollars per kWh.
How many kWh does a typical household use per month?
The US average residential household uses approximately 877 kWh per month, according to the US Energy Information Administration (EIA). This varies by climate (air conditioning and heating use), home size, and appliances. Southern states with hot summers average much higher (1,100–1,200 kWh); mild-climate states like California and Hawaii average lower (500–600 kWh).
What appliances use the most electricity?
Heating and cooling systems are typically the largest electricity consumers: central air conditioning (2,000–5,000W), electric water heaters (4,000–5,000W), and electric furnaces (10,000–15,000W). After HVAC, major appliances include clothes dryers (4,000–6,000W), refrigerators (100–400W running 24/7), and dishwashers (1,200–2,400W). LED lighting and modern TVs are relatively low consumers compared to older incandescent bulbs and CRT televisions.
How much can I save by switching from incandescent to LED bulbs?
A 60W incandescent bulb can be replaced by a 9W LED producing equivalent light (800 lumens). For a bulb used 5 hours per day at 15¢/kWh: Incandescent: 60W × 5hr × 30 days ÷ 1000 × $0.15 = $1.35/month. LED: 9W × 5hr × 30 days ÷ 1000 × $0.15 = $0.20/month. Savings: $1.15/month per bulb = $13.80/year per bulb. A home with 20 bulbs saves approximately $276/year.
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