Your electricity bill charges you per kilowatt-hour (kWh). Knowing how to convert appliance usage to kWh — and kWh to dollars — puts you in control of your energy spending.
The kWh Formula
kWh = (Watts × Hours Used) ÷ 1,000
Cost = kWh × Price per kWh
Example: A 1,200W microwave used for 30 minutes:
- kWh = (1,200 × 0.5) ÷ 1,000 = 0.6 kWh
- Cost at $0.16/kWh = 0.6 × $0.16 = $0.096 (~10 cents)
Current US Average Electricity Rates (2025)
| Region | Average Rate |
|---|---|
| US National Average | ~$0.16–$0.18/kWh |
| Hawaii (most expensive) | ~$0.38/kWh |
| Louisiana (cheapest) | ~$0.10/kWh |
| California | ~$0.28/kWh |
| Texas | ~$0.13/kWh |
| New York | ~$0.22/kWh |
Check your electricity bill for your exact rate — it is listed as cents per kWh or $/kWh.
Appliance Running Costs: Annual Estimates
Using $0.16/kWh national average:
| Appliance | Typical Wattage | Hours/Day | Monthly kWh | Monthly Cost |
|---|---|---|---|---|
| Central AC (3 ton) | 3,500 W | 8 hrs (summer) | 840 | $134 |
| Electric water heater | 4,000 W | 3 hrs | 360 | $58 |
| Electric dryer | 5,000 W | 1 hr | 150 | $24 |
| Refrigerator | 150 W | 24 hrs | 108 | $17 |
| Dishwasher | 1,200 W | 1 hr | 36 | $6 |
| Washing machine | 500 W | 1 hr | 15 | $2.40 |
| LED TV (55") | 100 W | 5 hrs | 15 | $2.40 |
| Desktop PC | 200 W | 8 hrs | 48 | $7.68 |
| Laptop | 50 W | 8 hrs | 12 | $1.92 |
| LED bulb (10W) | 10 W | 5 hrs | 1.5 | $0.24 |
| Phone charger | 5 W | 3 hrs | 0.45 | $0.07 |
| Gaming console | 150 W | 3 hrs | 13.5 | $2.16 |
Calculating Annual Cost for Any Appliance
Annual kWh = (Watts ÷ 1,000) × Hours per Day × 365
Annual Cost = Annual kWh × Rate
Example: 65-inch OLED TV at 120W, watched 5 hours/day, $0.18/kWh:
- Annual kWh = (120 ÷ 1,000) × 5 × 365 = 219 kWh
- Annual cost = 219 × $0.18 = $39.42/year
Understanding Your Electricity Bill
A typical US household uses 900–1,100 kWh per month (EIA data).
Your bill = kWh used × rate + fixed charges (delivery fees, taxes)
To find your effective rate:
Effective Rate = Total Bill ÷ Total kWh Used
The effective rate is often higher than the advertised energy rate because it includes transmission, distribution, and taxes.
Time-of-Use (TOU) Pricing
Many utilities charge more during peak hours (typically 4–9 PM weekdays):
| Period | Typical Rate |
|---|---|
| Off-peak (nights, weekends) | $0.10–$0.14/kWh |
| Mid-peak | $0.16–$0.20/kWh |
| On-peak | $0.25–$0.45/kWh |
Strategy: Run dishwasher, washing machine, and EV charging after 9 PM to avoid peak rates. In TOU pricing areas, this can reduce the electricity bill by 15–30%.
The Biggest Energy Savers
Targeting the highest-consumption appliances delivers the most savings:
- HVAC — Raising AC setpoint 2°F saves ~5–8% on cooling costs
- Water heating — Lowering tank temperature from 140°F to 120°F saves 4–8%
- Dryer — Cleaning lint trap, using moisture sensor setting, line drying when possible
- Refrigerator — Keeping coils clean, setting to 37–38°F fridge / 0°F freezer
- Lighting — Switching all remaining incandescent to LED (75% energy reduction)
kWh to CO₂ Emissions
For environmental context, the US average emission factor is approximately 0.386 kg CO₂ per kWh (EPA 2023):
CO₂ (kg) = kWh × 0.386
1,000 kWh/month household → approximately 386 kg CO₂/month from electricity.
Use our electricity usage calculator to enter your appliances and usage patterns and get a complete breakdown of your monthly energy cost.