Fill in amps and volts to calculate watts
Standby / Phantom Load Calculator
Devices in standby mode still draw power 24/7. The US DOE estimates a typical home wastes $50–100/year on standby power.
Find Your Electricity Rate
Look on your electricity bill for "energy charge", "rate per kWh", or "unit rate". Click any country below to use their average rate.
| Country / Region | Avg Rate | Notes |
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🕒 Multi-Appliance Calculator
Add multiple appliances to see your combined running cost. Uses the rate set above.
| Appliance | Watts | Hrs/day | Days/wk | Cost/day | Cost/mo |
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Common Appliance Wattage Reference
Click any appliance to pre-fill the calculator. Wattage ranges are typical — check your appliance label for exact values.
| Appliance | Typical Range | Typical Value | Category |
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How to Calculate Appliance Electricity Cost
Your electricity bill is measured in kilowatt-hours (kWh). One kWh is the energy used by a 1,000W device running for 1 hour. To find the cost of running any appliance:
- Find the wattage — on the appliance label, power supply, or manual
- Convert watts to kilowatts — divide by 1,000 (e.g., 1,500W ÷ 1,000 = 1.5 kW)
- Multiply by hours used per day — e.g., 1.5 kW × 4 hours = 6 kWh/day
- Multiply by your rate — e.g., 6 kWh × $0.16 = $0.96/day
- Scale to monthly/yearly — multiply by 30 for monthly, 365 for yearly
The Formula
Monthly Cost = Daily Cost × (Days/Week ÷ 7) × 30
Yearly Cost = Daily Cost × (Days/Week ÷ 7) × 365
kWh/Day = Watts ÷ 1000 × Hours/Day
CO₂/Month = kWh/Month × 0.4 kg/kWh (grid average estimate)
Worked Example: 100W Bulb Running 24 Hours at $0.15/kWh
kWh/day = 100 ÷ 1000 × 24 = 2.4 kWh/day
Daily cost = 2.4 × $0.15 = $0.36/day
Monthly cost = $0.36 × 30 = $10.80/month
Yearly cost = $0.36 × 365 = $131.40/year
Understanding kWh
A kilowatt-hour is simply energy. Think of it as running a 1,000W appliance for exactly 1 hour. Your electricity meter counts how many kWh you use, and your utility bills you per kWh. In the US, the average residential rate was $0.16/kWh in 2024; it ranges from $0.10/kWh (Louisiana) to $0.35+/kWh (Hawaii and some New England states).
Most Expensive Appliances to Run
High-wattage appliances that run frequently dominate your electricity bill. Here are the biggest consumers:
- Central Air Conditioner (2,000–5,000W) — Running 8 hrs/day in summer at $0.16/kWh costs $5–13/day. Central AC is typically the largest single line item on summer electricity bills.
- Electric Water Heater (3,000–4,500W) — Runs intermittently but often totals 3–5 kWh/day for a family. Annual cost: $175–290.
- Electric Dryer (4,000–6,000W) — Each cycle (~45 min) costs $0.48–$0.72. Three loads per week = $75–112/year.
- Space Heater (750–1,500W) — Running 8 hrs/day costs $0.96–$1.92/day. A 1,500W heater running all winter adds $100–200/year if used frequently.
- Pool Pump (750–2,500W) — Running 8 hrs/day costs $0.96–$3.20/day. Annual cost: $350–1,170 for daily pool filtration.
- Electric Vehicle Charger (Level 2: 7,200W) — Charging 1 hour adds ~7.2 kWh. Charging 10 hrs/week costs about $4.60/week or $240/year at $0.16/kWh.
- Refrigerator (100–250W, runs 24/7) — Cycles on and off; effective average ~150W. Annual cost: $75–150 depending on size and age.
- Desktop PC + Monitor (150–400W) — Running 8 hrs/day costs $0.19–$0.51/day, or $70–187/year.
How to Lower Your Electricity Bill
Quick Wins (Low or No Cost)
- Switch to LED bulbs — An LED uses 8–12W vs. a 60W incandescent for the same light. Switching 10 bulbs saves ~$80/year at average US rates.
- Unplug standby devices — Use smart power strips or simply unplug chargers, game consoles, and TVs. The DOE estimates $50–100/year in standby waste per home.
- Set your thermostat wisely — Each 1°F reduction in AC setpoint saves about 1–3% on cooling costs. A programmable or smart thermostat pays for itself in under 2 years.
- Wash clothes in cold water — ~90% of the energy for a wash cycle goes to heating water. Cold-water detergents are equally effective.
- Run full loads — A dishwasher or washing machine uses the same energy whether half full or full. Wait for full loads.
- Clean refrigerator coils — Dusty coils make the compressor work harder. Cleaning them annually can improve efficiency by 15–30%.
Bigger Investments (Highest ROI)
- Heat pump water heater — 3–4× more efficient than resistance heating. Saves $300–500/year vs. a standard electric water heater.
- Air sealing and insulation — The cheapest "appliance upgrade" is stopping conditioned air from escaping. Weatherstripping and attic insulation often yield 15–20% total bill reduction.
- Energy Star appliances — An Energy Star refrigerator uses 9–20% less energy; a certified dishwasher ~12% less. Look for the label when replacing appliances.