Electricity Calculator
Reveal the hidden energy costs in your home and take control of your utility bills.
Electricity Calculator
Your electricity bill is made up of every appliance in your home running for hours every day. This electricity calculator shows you exactly how much power each device uses and what it's costing you — so you can make smarter energy decisions.
What Does This Calculator Do?
Enter the wattage of an appliance, how many hours per day you use it, and your electricity rate (cents per kWh), and the calculator returns your daily, monthly, and annual electricity cost for that device.
How to Use This Calculator
- Enter the appliance wattage (found on the device label or manual).
- Enter the hours per day the appliance runs.
- Enter your electricity rate in cents per kWh (check your utility bill).
- Click Calculate to see energy usage and cost.
Electricity Cost Formula
kWh = (Watts × Hours per Day) ÷ 1,000
Daily Cost = kWh × Rate ($/kWh)
Monthly Cost = Daily Cost × 30
Annual Cost = Daily Cost × 365
Example Calculation
A 1,500-watt space heater running 6 hours/day at $0.13/kWh:
- kWh/day = (1,500 × 6) ÷ 1,000 = 9 kWh/day
- Daily cost = 9 × $0.13 = $1.17/day
- Monthly cost = $1.17 × 30 = $35.10/month
- Annual cost = $1.17 × 365 = $427.05/year
Typical Appliance Wattages
- Refrigerator: 100–400W
- Air conditioner (central): 2,000–5,000W
- Electric dryer: 4,000–6,000W
- TV (LED, 55"): 80–100W
- Desktop computer + monitor: 150–300W
- LED light bulb: 8–15W
- Phone charger: 5–20W
Why Use This Calculator?
Most people have no idea which appliances are costing them the most. A single space heater running 8 hours a day can add $50+ per month. This calculator reveals the hidden costs — so you can prioritize where to cut back or upgrade to energy-efficient models.
Common Mistakes to Avoid
- Using peak wattage for continuous devices — some appliances list their maximum wattage, but cycle on and off. A refrigerator might be rated 400W but only runs 40% of the time.
- Ignoring standby power — TVs, game consoles, and chargers draw power even when "off." These phantom loads can account for 5–10% of your electricity bill.
- Using the wrong electricity rate — check your actual utility bill for your rate. Rates vary from $0.08 to $0.30/kWh depending on location and time of use.
Frequently Asked Questions
What is a kilowatt-hour?
A kilowatt-hour (kWh) is the amount of energy used by a 1,000-watt appliance running for one hour. It's the unit your utility company uses to bill you.
How much does it cost to run a TV all day?
A 100W TV running 8 hours = 0.8 kWh. At $0.13/kWh, that's about $0.10/day or $3/month.
What uses the most electricity in a home?
Heating and cooling (HVAC) typically accounts for 40–50% of a home's electricity use, followed by water heating, appliances, lighting, and electronics.
How do I find the wattage of an appliance?
Check the label on the back or bottom of the device. It will show watts (W) or amps (A) and volts (V). If only amps and volts are listed: Watts = Amps × Volts.
Will switching to LED bulbs save money?
Yes significantly. An LED uses 8–10W vs. 60W for an incandescent. Over 1,000 hours, that's 50kWh saved per bulb — at $0.13/kWh, about $6.50 in savings per bulb per 1,000 hours.
Conclusion
Understanding your electricity usage is the first step to lowering your energy bill. Use this calculator to audit your biggest appliances — you might be surprised where most of your money is going.
Related: Voltage Drop Calculator | Ohm's Law Calculator | Budget Calculator
Efficiency Tip
Phantom loads (standby power) account for roughly 5-10% of residential energy use. Unplugging devices like game consoles when not in use can save you $100+ per year.
