Electricity usage is calculated in kilowatt-hours. A kilowatt-hour is 1,000 watts used for one hour. As an example, a 100-watt light bulb operating for ten hours would use one kilowatt-hour.
How to calculate electric usage cost:
1. Volts x Amps = Watts
2. Watts ÷ 1,000 = Kilowatts (kW)
3. Kilowatts (kW) x Hours of Use = Kilowatt Hours (kWh)
4. Kilowatt
Hours (kWh) x kWh rate = Cost of Usage
5. Add TVA Power Cost Adjustment charge per kWh
Below are some examples of electrical appliances found in most homes. These examples are using a 10 cents per kWh rate.
Appliance/Equipment | Avg. Usage | Monthly kWh | Cost/Month |
Comfort & Health | |||
Air Conditioner – Window 12,000 BTU (1,400 Watts) | 8 hours/day | 341 | $34.10 |
Dehumidifier (257 Watts) | 12 hours/day | 94 | $9.40 |
Fan – Furnace (300 Watts) | 7 hours/day | 64 | $6.40 |
Fan – Ceiling (125 Watts) | 12 hours/day | 46 | $4.60 |
Fan – Attic (1000 Watts) | 2 hours/day | 61 | $6.10 |
Heat Pump (Average Rating) (1,800 sq. ft. house) 7.7 HSPF* | daily | Average Annual Cost | $841.50 |
Heat Pump (High Efficiency) (1,800 Sq. ft. house) 8.5 HSPF* | daily | Average Annual Cost | $762.30 |
Heat Pump (Geothermal) (1,800 sq. ft. house) Equiv. 13.3 HSPF* | daily | Average Annual Cost | $487.10 |
Heater – Portable (1500 W) | 8 hours/day | 365 | $36.50 |
Humidifier (177 Watts) | 8 hours/day | 43 | $4.30 |
Water Heater (4500 W) | 3 hours/day | 411 | $41.10 |
Hair Dryer (1,000 W) | 15 min./day | 7.6 | $0.76 |
*Heating Season Performance Factor (an efficiency rating) **Based on 4,296 Heating Degree Days. Cooling costs would be approximately 40% of total energy costs. | |||
Food Prep. & Preservation | |||
Blender/Food Processor (400 Watts) | 1 hour/week | 2 | $0.20 |
Coffee Maker (894 Watts) | one hour/day | 27 | $2.70 |
Dishwasher (1,200 Watts) (excludes hot water costs) | one hour/day | 37 | $3.70 |
Microwave Oven (1,450 W) | 30 min./day | 22 | $2.20 |
Range (12,200 Watts) | 30 min./day | 186 | $18.60 |
Freezer 15 Cu. Ft. (341 W.) | 12 hrs/day | 124 | $12.40 |
Refrigerator – 14 Cu. Ft. (440 W.) | 12 hrs/day | 161 | $16.10 |
Refrigerator – 18 Cu. Ft. (manual defrost – deduct 35%) | 12 hrs/day | 180 | $18.00 |
Laundry | |||
Clothes Dryer (4,900 W) | 6 loads/week | 90 | $9.00 |
Washer (512 Watts) (Excludes water costs) | 6 loads/week | 9 | $.90 |
Home Entertainment/Recreation | |||
42″ Plasma TV (320 Watts) (instant-on tvs use some electricity continuously) | 35 hours/week | 44.8 | $4.48 |
Home Computer (500 W) Including Monitor | 4 hours/day | 61 | $6.10 |
Hot Tub (5,000 W) | 2 hrs/day | 304 | $30.40 |
Pool Heater (incl. motor) | avg/daily | 670 | $67.00 |
Pool Pump (1 hp) | continuous | 1240 | $124.00 |
Lighting | |||
40-Watt Bulb (40 W) Equivalent compact fluorescent | 4 hours/day 4 hours/day | 5 1.375 | $.50 $.14 |
60-Watt Bulb (60 W) Equivalent compact fluorescent | 4 hours/day 4 hours/day | 7 1.625 | $.70 $.16 |
75-Watt Bulb (75 W) Equivalent compact fluorescent | 4 hours/day 4 hours/day | 9 2.5 | $.90 $.25 |
100-Watt Bulb (100 W) Equivalent compact fluorescent | 4 hours/day 4 hours/day | 12 3.25 | $1.20 $.33 |
Farm | |||
Electric Fence Charger | daily | 2 | $.20 |
Heater (tractor engine block) (600W) | 10 hrs/day | 182 | $18.20 |
Heater (livestock tank) | 8 hrs/daily | 365 | $36.50 |
Auto Battery Charger (600W) | 2 hours | 36 | $3.60 |
Well Pump (750-1000W) | avg./10% usage | 40 | $4.00 |
For other tips on saving energy visit the Department of Energy Web site, Energy Savers – Tips on Saving Energy and Money at Home
How many kW of energy does a house use per day?
If the median watt-hours of a home per day is 30,000, to find out how many kilowatts it takes to run a house using direct calculations, simply divide the wattage by 1000 to get 30. That means that the average kW used in U.S. households is 30kW per day, which averages at around 900kW per month.
What is the average kWh per day UK?
According to Ofgem, the average household in the UK has 2.4 people living in it, and uses 8 kWh of electricity and 33 kWh of gas respectively, per day. This works out as an average of 242 kWh or electricy and 1,000 kWh of gas per month, or 2,900 kWh of electricity and 12,000 kWh of gas each year.
Is 30 kWh a day a lot UK?
The following figures give an estimate of the average electricity usage and average gas usage per day in the UK: Electricity - between 8 and 10 kWh per day. Gas - between 33 and 38 kWh per day.
How many kWh is needed to power a house?
According to data from 2020, the average amount of electricity an American home uses is 10,715 kilowatt-hours (kWh). If you divide this number by 12 (months in a year), the average residential utilities customer uses 893 kWh per month.