Laptop Wattage – How many Watts does it take to charge a laptop?

Perhaps you are wondering how many watts a laptop consumes?

There are a few things to consider, including the laptop’s battery life.

An important aspect of your laptop’s performance is its power consumption. It’s essential to have a long-lasting laptop battery if you’re planning on taking your laptop on long trips or to places where you can’t plug it in.

If you want to find out how long your laptop’s battery will last, you’ll have to know how many watts it uses.

Compared to desktop PCs with external monitors, mobile devices such as laptops consume less power. Batteries of laptops are typically fully charged once a day, and the power it takes to charge a laptop varies between 20 and 50 watts. This calculation assumes that 70% of the energy for the charging process is transferred to the battery, with 30% passing to the environment as waste heat.

An example of a typical household laptop would be the HP 15 by Hewlett Packard. It takes 41W to fill this machine’s battery. It is, of course, subject to fluctuation. Throughout the life of a device, the wattage of a power supply may vary depending on the power dissipation. As a result of the relatively small variance, however, it is more or less negligible.

You should keep in mind that good battery quality reflects in the charging process. It’s either you replace the cells in your battery or you purchase a new battery if your laptop battery stops working.

Watt’s Depends on?

The wattage of your computer – how many watts it consumes – is the measurement of how much power it consumes. If your laptop consumes more power, it will drain its battery faster.

Laptops use a wide range of power, which makes it difficult to say how much power they consume. For some laptops, the power consumption can reach 180 watts per hour. Most laptops require between 20 and 100 watts per hour.

The reasons for using a laptop are often reflected in these variations. There are different types of hardware and usages for different needs. You can expect your laptop to consume more power if you plan to play video games or use programs that require high-quality graphics.


Laptop adapters connect to the main system via the power supply. Laptops with larger screens require more powerful adapters.

If you are thinking about upgrading your computer, keep this in mind. If you add anything to your laptop, make sure it’s compatible with the power supply


Computers are controlled by their central processing unit (CPU), which is the computer’s brain. Computers operate programs to translate what you do into reality-whether you’re searching for something, designing a home, or playing fast-action games.

There are, however, differences between CPUs. A high-quality CPU will use less power and be more efficient.

Graphics Card

A laptop’s graphics card determines the quality of its display. You can run your laptop with a lower grade graphics card if all you need it for is browsing the Internet and running spreadsheets.

For gaming or computer-aided design (CAD) programs, you will need a more powerful graphics card. The better the graphics card, the better the computer’s performance, but it requires a more powerful power supply.

Screen Size

Laptop screens use the most battery power. You will use more battery when your screen is larger.

Laptop screens usually consume about 60 watts per hour. However, you can increase your wattage by as much as 100 watts per hour when you choose a larger model.

Factors Affecting the Power Consumption of Laptops

Factors Affecting the Power Consumption of Laptops

Factors Affecting the Power Consumption of Laptops

Despite the fact that laptops have many functions and large computing capacities, they are often designed in a way that’s energy-efficient. A display and a processor are typically large consumers. Electricity consumption consists of three main components:

  • Graphics card
  • Display
  • Processor
  • Random Access Memory (RAM)
  • Hard disk / SSD
  • WLAN module
  • Fan
  • Touchpad

Modern laptops with multi-core processors can consume as much as 60 watts while heavily used. It is important to consider the graphics card. As soon as a graphics card is installed, the laptop’s power consumption increases tremendously. However, gaming laptops and high-end laptops typically have dedicated graphics cards.

Wattage Calculation for Your Laptop

The hardware mentioned above is necessary for a laptop to function. There will, however, be differences between brands and models.

Checking a laptop’s adapter will tell you roughly how many watts it uses. You can find out your laptop’s maximum input power through the adapter. An accurate figure of its power consumption can be determined with a little effort.

Wattage Calculation for Your Laptop

Wattage Calculation for Your Laptop

Check the components – The component specifications can be found on the website of each manufacturer. Even if you add them together, you still won’t be able to determine how much power is consumed by your laptop. When going online to find the power consumption of your laptop, you can input the figures.

A power consumption monitor can be used to find out how much power your laptop consumes. With one of these devices, you can determine the power consumption of your laptop and how many watts it uses in real-time.


Using the information on the bottom of the device, you can easily calculate the wattage consumed by a laptop charger. Input only shows the device’s working voltages. As a result, you should take the output values. You get the power consumption when you multiply volts by amps.

At full power, the power consumption can be slightly higher than calculated. A notebook charger always delivers less current than it draws from the network, which is usually around 70% depending on the device. Therefore, an ammeter is the only way to determine the exact value.