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Electricity bills are a monthly expense that many individuals and families have to pay. Although the unit price for some electricity will be different depending on the amount of consumption, electric companies nationwide apply the same formula for calculating power consumption. This general formula will produce the electricity number for each household, which will then be multiplied by the unit price to get the total bill. Many customers are curious to know how to calculate electricity bills because sometimes there are months when the cost is too high. At the same time, knowing how to calculate also helps families find solutions to save more electricity. In the following article, Hoang Ha Mobile will guide you in the simplest way to calculate electricity consumption and monthly electricity bill.

Basic electricity consumption formula for families

To calculate power consumption, users need to clearly know the capacity and usage time of a device. Each household electrical appliance will have a different consumption rate. This information has been mentioned in detail right in the technical specifications printed on the device or pasted on the cover. Before calculating power consumption, users need to accurately review indicators such as power consumption, serial number, place of origin… to ensure the error is not too large.

The formula for calculating electricity consumption is extremely simple, has been mentioned in junior high school Physics and is highly applicable. This formula will give you a relatively accurate result compared to the electricity number on the meter, depending on the operating status of each type of electrical equipment. The formula for calculating power consumption is written in standard notation as follows:

A = P * t

In there:

• A is the power consumption of the device
• P is the power consumption of the device (available at technical specifications)
• t is the device usage time

This formula can be applied to calculate electricity by hour, day or month and can be used for all devices in the family. The total amount of electricity consumed will be equal to the total amount of electricity used by each device combined. On this basis, households will be able to estimate the amount of money they have to pay for their electricity bill in a relatively accurate month.

Formula to calculate power consumption for each household appliance

Each electrical appliance in the house will have a different consumption rate and frequency of use. To calculate the total electricity consumption of the whole family, users need to calculate each device individually and add them together. Power consumption is often printed right on the surface of each device, users rely on that to find the correct P number. In addition to appliances that must be used 24/7 such as refrigerators, users can estimate the average time t per day for intermittently used appliances.

The following is the most detailed example illustrating how to calculate the power consumption of a few common household electrical appliances. Note, the mentioned power consumption numbers are not correct in all cases, you should change flexibly according to your family to get more accurate results.

Power consumption of the refrigerator

Refrigerators are essential equipment that every family has, often used 24/7 to preserve food and drinks. Therefore, when applying the formula to calculate power consumption, users will not need to estimate the average time. On average, refrigerators will have an operating capacity of about 120W, so to calculate the amount of electricity consumed in a day, you only need to take A = 120W (0.12kW) * 24h = 2.88kW. To calculate by month, users multiply by 30 or 31 days depending on the month.

In addition, many refrigerators also directly record the amount of electricity consumed in a year. Households can take that total amount of electricity and divide it by 356 days to get daily electricity consumption or divide it by 12 months to get average monthly electricity consumption. Besides, if you use more than 1 refrigerator, you can also multiply it by the number of appliances being used in the family.

Power consumption of televisions and rice cookers

Television usage frequency is not too high, especially in the era of rapid development of technological devices such as phones and computers. On average, a family today only spends 4-5 hours/day watching TV, and some families don't even use it at all. Therefore, estimating TV usage time is quite difficult and can lead to errors.

Normally, a 14-inch TV will consume about 1kW in 25 hours of use (P=40W) according to the power consumption formula, while an 18-inch TV will consume about 1kW in 15.4 hours (P=65W). Depending on the size, each TV will have a different power level, this index is also clearly stated on the user manual.

Rice cookers have less usage time as it only takes about 20-30 minutes to plug in rice, but almost every day you need to use it about 1-2 times. According to calculations, a 500W pot will consume about 1kW in 2 hours, a 750W pot will need about 1kW in 1.3 hours of use.

Power consumption of front-load washing machine

For washing machines, operating capacity often depends on capacity and front and top door design. Although used sparingly, usually about once a day, for about 1-2 hours each time, this is one of the devices with a relatively large power consumption. In particular, washing machines also combine smart drying and rinsing, with many washing modes consuming more electricity. A mid-range machine usually has a capacity of about 1240W, meaning that in 1 hour of washing, the machine will consume about 1.24kW.

However, the formula for calculating the power consumption of a washing machine may be different if the user applies an economical washing mode, or only uses it for rinsing and spinning. Therefore, you can flexibly re-estimate P accordingly and choose the most reasonable time number t.

Power consumption of hair dryer and vacuum cleaner

A hair dryer is a household electrical appliance that is relatively small in size and has a relatively short usage time. On average, a hair dryer only consumes about 1kW in 1 hour of continuous use. If you only use it for about 15 minutes, the amount of electricity consumed is only about 1/4 of the above figure. This is also the maximum amount of electricity if the user uses it with the highest heat level and fan speed. The amount of electricity consumed by the dryer depends on the drying level and type of dryer.

The formula for finding the amount of electricity consumed can also be applied to a vacuum cleaner, giving a result of about 1.8kW in 1 hour with maximum suction power. If the family only uses moderate suction power, the amount of electricity lost will only be around 1kW.

Formula to calculate power consumption of air conditioner

For weather outside the North, air conditioning is mostly used in the summer, when the heat is at its peak. There are also many families that use heating mode with 2-way air conditioning in the winter, but it usually lasts for a short time and not most households use it. Many customers will think that air conditioners have high operating capacity, but on average each air conditioner is only about 800-850W, much lower than other electrical devices. Thus, according to the formula, a 9000BTU air conditioner only consumes about 0.85kW in 1 hour of use.

The formula for calculating power consumption is easy to apply to a variety of devices if you know the capacity and usage time. However, manual application will sometimes lead to significant errors if you add the total too many times. Operating capacities printed on the device or user manual often refer to the maximum P level, which means the power level you calculate is the maximum consumption of the device in the specified time.

In particular, the development of Inverter technology is also a solution that helps many families save heavy electricity and significantly reduce costs. Therefore, users should not apply the formula too rigidly because the results obtained are only relative and errors cannot be avoided.

Calculate the electricity bill based on the formula for calculating power consumption

To calculate the entire month's electricity bill, customers need to know the amount of electricity consumed by all electrical appliances in a month. Of course, you do not need to calculate manually for each type of appliance because this index is clearly displayed on the electricity meter. Users only need to remember the input index at the beginning of the month and the final index at the end of the month, then subtract to get the amount of electricity consumed. There are different fees for different levels of electricity usage. The following is the invoice calculation formula:

Electricity bill = Number of electricity consumed at level N x Unit price of electricity at level N

According to the latest Regulations of Vietnam Electricity Group, applied from November 9, 2023, electricity retail prices are divided into 6 levels with different fee schedules. According to convention, 1kW that you calculate according to the power consumption formula will be a number of electricity.

• Level 1: 0 – 50 electricity numbers with 1,806 VND/kWh
• Level 2: 51 – 100 electricity numbers with 1,866 VND/kWh
• Level 3: 101 – 200 electricity numbers with 2,167 VND/kWh
• Level 4: 201 – 300 electricity numbers with 2,729 VND/kWh
• Level 5: 301 – 400 electricity numbers with 3,050 VND/kWh
• Level 2: over 400 electricity numbers with 3,151 VND/kWh

For example, if you consume 238 electricity in a month, you will apply the calculation formula for level 4, meaning the electricity bill to pay is 544,322 VND for that month. In addition, electricity prices for business purposes will also be higher than residential electricity.

Website calculates monthly electricity bill accurately for customers

With the support of specialized websites for calculating bills, customers now do not need to manually calculate their electricity bills using the formula to calculate power consumption. EVN's official information page provides users with an extremely fast and accurate electricity bill calculation tool. When accessing and using this function, you only need to enter some basic information, then the system will automatically recognize the power number and give you the results. Regarding electricity consumption, families can monitor the readings on the electricity meter, this is the most accurate result for the amount of electricity used in a month.

Step 1: Access the Electricity Bill Calculator Tool via the link: https://cskh.cpc.vn/tra-cuu/cong-cu-tinh-toan-tien-dien

This includes the retail electricity price list according to the latest decision issued and applied nationwide for users' reference. This website also applies a billing method based on the formula for calculating power consumption like the manual calculation you usually do.

Step 2: Enter the requested information, including:

• Electricity usage time (from which day to which day of the month)
• Total electricity consumption (kWh): See the index on the electricity meter
• Number of households using electricity

Step 3: Click here Calculatethen the Results table will display the detailed calculation and the final amount to be paid is highlighted in extremely prominent red.

Conclusion

Although the calculation results are only relative, understanding the amount of electricity consumed by household appliances is also a way for users to find effective electricity saving solutions. The formula for calculating electricity is not too complicated and can be applied in many cases and devices. In particular, knowing how to calculate your electricity bill will help you worry less about the monthly cost, as well as answer questions about why the bill has such a total amount. In case users are afraid of making errors or making calculations, EVN's tool will help you do it quickly and extremely accurately.

Hope the information provided about formula for calculating power consumption The article above has helped readers clarify how to calculate monthly electricity consumption. Don't forget to follow Hoang Ha Mobile to stay up to date with the latest technology news and useful life tips.

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