Electricity Cost Calculator

There are several ways to find an appliance's wattage: CHECK THE LABEL: Most appliances have a label or plate (usually on the back or bottom) showing power consumption. Look for "W" (watts), "kW" (kilowatts), or power rating. Example: "120V 60Hz 1500W" means 1500 watts. CHECK THE MANUAL: The specifications section lists wattage. Online manuals are available for most products. CALCULATE FROM AMPS AND VOLTS: Watts = Volts × Amps. US appliances are typically 120V. Example: 10A device at 120V = 1,200 watts. USE A POWER METER: Plug-in meters (like Kill A Watt) measure actual usage. Shows real-time and cumulative consumption. Most accurate method. TYPICAL RANGES: LED bulb: 8-15W. Laptop: 30-70W. TV: 50-150W. Refrigerator: 100-400W. Air conditioner: 500-3000W. Electric heater: 750-1500W. NOTE: Wattage on label is maximum. Actual usage may vary based on settings (e.g., AC on high vs. low).

Electricity cost is calculated using a simple formula: THE FORMULA: Cost = (Watts ÷ 1000) × Hours × Rate per kWh. STEP-BY-STEP: 1. Convert watts to kilowatts: Divide wattage by 1000. Example: 1500W ÷ 1000 = 1.5 kW. 2. Calculate energy used: Multiply kW by hours of use. Example: 1.5 kW × 8 hours = 12 kWh. 3. Calculate cost: Multiply kWh by your electricity rate. Example: 12 kWh × $0.15/kWh = $1.80. UNDERSTANDING kWh: kWh = kilowatt-hour. It's a unit of energy, not power. 1 kWh = using 1000 watts for 1 hour. OR using 100 watts for 10 hours. YOUR ELECTRICITY RATE: Found on your utility bill. Varies by location ($0.10 to $0.40+/kWh). May have tiered rates (higher usage = higher rate). May vary by time of day (time-of-use rates). EXAMPLE CALCULATION: 100W TV watched 5 hours/day at $0.15/kWh: Daily: (100 ÷ 1000) × 5 × $0.15 = $0.075. Monthly: $0.075 × 30 = $2.25. Yearly: $0.075 × 365 = $27.38.

The biggest electricity users are typically heating and cooling equipment: TOP ELECTRICITY CONSUMERS: 1. Central Air Conditioning: 3,000-5,000W. Can use 3,000+ kWh/year. Often 25-50% of summer electric bill. 2. Electric Water Heater: 4,000-5,500W. Uses 400-500 kWh/month. About 18% of home energy use. 3. Electric Dryer: 2,000-5,000W. ~5 kWh per load. 4. Electric Oven/Range: 2,000-5,000W. Varies greatly by cooking frequency. 5. Space Heaters: 750-1,500W. Very expensive if used frequently. 1,500W heater running 8 hours = $1.44/day (at $0.12/kWh). 6. Pool Pump: 1,000-2,500W. Runs 8-12 hours/day. 7. Refrigerator: 100-400W. Runs 24/7, so adds up. 400-600 kWh/year typical. 8. Electric Vehicle Charging: 3,000-7,500W. 10-40 kWh per full charge. PHANTOM LOADS (always-on): DVR/Cable box: 15-40W (24/7). Gaming console (standby): 1-25W. Phone charger (plugged in): 0.1-0.5W. Desktop computer (sleep): 1-5W. These add $50-100/year to bills.

Here are proven strategies to lower your electricity bill: HEATING & COOLING (40-50% of bill): Set thermostat 1-2° higher in summer, lower in winter. Each degree saves ~3% on heating/cooling costs. Use ceiling fans (pennies per hour vs. dollars for AC). Seal air leaks around windows and doors. Use a programmable or smart thermostat. WATER HEATING (14-18% of bill): Lower water heater to 120°F. Take shorter showers. Use cold water for laundry (saves 90% of wash energy). Fix leaky faucets. LIGHTING (5-10% of bill): Switch to LED bulbs (use 75% less energy). Turn off lights when leaving rooms. Use natural daylight when possible. Install motion sensors or timers. APPLIANCES & ELECTRONICS: Unplug devices when not in use (eliminates phantom load). Use power strips for electronics. Run dishwasher and laundry with full loads. Air dry clothes when possible. Choose ENERGY STAR appliances. BEHAVIORAL CHANGES: Shift high-energy tasks to off-peak hours (if on time-of-use rates). Use microwave instead of oven for small meals. Keep refrigerator coils clean. TYPICAL SAVINGS: LED switch: $100+/year. Smart thermostat: 10-15% on heating/cooling. Eliminating phantom loads: $50-100/year. Energy-efficient appliances: 10-50% per appliance.

Electricity rates vary significantly by location and utility: NATIONAL AVERAGE (2024): Residential: ~$0.16 per kWh. Commercial: ~$0.13 per kWh. Industrial: ~$0.08 per kWh. STATE VARIATIONS: HIGHEST RATES: Hawaii: $0.43/kWh. California: $0.27/kWh. Massachusetts: $0.26/kWh. Connecticut: $0.25/kWh. Rhode Island: $0.24/kWh. LOWEST RATES: Louisiana: $0.10/kWh. Oklahoma: $0.10/kWh. Idaho: $0.10/kWh. Washington: $0.11/kWh. North Dakota: $0.11/kWh. WHY RATES DIFFER: Fuel sources (coal, natural gas, hydro, nuclear). Infrastructure costs. State regulations. Renewable energy mandates. Transmission distances. RATE STRUCTURES: Flat rate: Same price all day. Tiered: Higher rate as usage increases. Time-of-use (TOU): Higher rates during peak hours. Demand charges: Based on peak usage (mainly commercial). FINDING YOUR RATE: Check your utility bill. Look for "price per kWh" or "energy charge". May have multiple components (delivery, supply, taxes). Average all-in rate = total bill ÷ total kWh used.

Air conditioning costs depend on several factors: TYPICAL AC WATTAGES: Window unit (5,000 BTU): 500W. Window unit (12,000 BTU): 1,200W. Portable AC: 900-1,400W. Central AC (3 ton): 3,000-3,500W. Central AC (5 ton): 5,000-6,000W. COST EXAMPLES (at $0.15/kWh): WINDOW UNIT (1,200W): Running 8 hours/day. Daily cost: 1.2 kW × 8 hrs × $0.15 = $1.44. Monthly cost: $1.44 × 30 = $43.20. Summer season (4 months): ~$173. CENTRAL AC (3,500W): Running 8 hours/day. Daily cost: 3.5 kW × 8 hrs × $0.15 = $4.20. Monthly cost: $4.20 × 30 = $126. Summer season: ~$500. FACTORS AFFECTING COST: Thermostat setting (each degree cooler costs ~3% more). Home insulation quality. Outdoor temperature. AC efficiency (SEER rating). Maintenance (dirty filters increase costs 5-15%). MONEY-SAVING TIPS: Use fans to feel 4°F cooler. Set to 78°F when home, 85°F when away. Use a programmable thermostat. Seal air leaks. Keep blinds/curtains closed. Service AC annually. Consider a more efficient unit (SEER 16+ vs. old SEER 10). CALCULATION SHORTCUT: Monthly AC cost ≈ (Watts ÷ 1000) × hours/day × 30 × your $/kWh.

A kilowatt-hour (kWh) is the standard unit used to measure and bill electricity: DEFINITION: 1 kWh = using 1,000 watts of power for 1 hour. It's a unit of ENERGY, not power. Power (watts) × Time (hours) = Energy (watt-hours). EXAMPLES OF 1 kWh: Running a 100W light bulb for 10 hours. Running a 1,000W microwave for 1 hour. Running a 50W fan for 20 hours. Running a 2,000W hair dryer for 30 minutes. UNDERSTANDING THE RELATIONSHIP: Watts = rate of energy use (like speed). kWh = total energy used (like distance). A 100W bulb uses energy at a rate of 100 watts. In 10 hours, it uses 1,000 watt-hours = 1 kWh. WHY kWh MATTERS: This is what you pay for on your electric bill. Typical home uses 900-1,000 kWh/month. At $0.15/kWh, that's $135-150/month. VISUALIZING 1 kWh: Power a TV for about 10 hours. Run a dishwasher once. Do one load of laundry. Bake for about 30 minutes. Run central AC for about 15-20 minutes. COMMON CONFUSION: kW (kilowatt) = power (rate). kWh (kilowatt-hour) = energy (total used). A 3 kW AC doesn't use 3 kWh instantly. It uses 3 kWh if it runs for exactly 1 hour. Running 8 hours = 24 kWh.

Yes, unplugging can save money by eliminating "phantom" or "vampire" power: WHAT IS PHANTOM POWER? Electricity used by devices when "off" but still plugged in. Powers standby modes, clocks, sensors, and instant-on features. Accounts for 5-10% of household electricity use. Average home: $100-200/year in phantom loads. BIGGEST PHANTOM LOAD CULPRITS: Cable/DVR box: 20-45W (even when "off"). Gaming console: 1-25W in standby. Desktop computer: 1-5W when sleeping. TV: 1-5W when off. Microwave (with clock): 2-5W. Phone charger (plugged in): 0.1-0.5W. Coffee maker (with clock): 1-2W. WHAT TO DO: HIGH IMPACT (worth unplugging): Home entertainment systems. Desktop computers and monitors. Gaming consoles. Older appliances without ENERGY STAR. LOW IMPACT (minimal savings): Phone chargers (when not charging). Modern ENERGY STAR appliances. Items used frequently. EASIER SOLUTIONS: Smart power strips: Cut power automatically. Timer outlets: For devices like coffee makers. Smart plugs: Control via phone. Turn off power strip, not individual items. WHEN NOT TO UNPLUG: Refrigerator/freezer (never). DVR if recording shows. Devices that take long to restart. Security systems. IS IT WORTH IT? If you unplug 200W of phantom loads: Daily savings: 4.8 kWh × $0.15 = $0.72. Monthly savings: ~$22. Yearly savings: ~$260. Worth it for high-draw items; less so for phone chargers.