How Many Watts Does a Laptop Charger Use? 2021 Guide

When mobile devices such as laptops are hooked into the wall rather than an external display, they consume less electricity. Generally, it is assumed that a laptop battery charges completely each day, though it may require less than 20W in some situations.

As a result, 70% of the energy is retained in the charger and 30% is released as heat into the atmosphere.

This Hewlett-Packard 15 computer is a good example of a standard home computer. This item requires 41W to recharge the battery. Naturally, like with any other piece of information or data, its value varies.

Each power supply unit dissipates a different amount of energy. Though the fluctuations are extremely small, they are not a significant issue.

The capacity of a battery is a good indicator of its performance. If your laptop’s battery dies, you must purchase a replacement.

HHow Many Watts Does a Laptop Charger Use?

According to the most recent estimate from the US Department of Energy, a normal laptop charger consumes 50 watts of electricity, or 5 kilowatt hours.

On average, a WH suggests that if a laptop is used for eight hours per day, it will cost 5p per day to operate.

Charging is Tied to Power Consumption

A massive notebook, even when idle, consumes more power than a tablet PC when performing computationally intensive tasks. A larger battery takes longer to charge than a smaller battery.

The Larger Laptop: ThinkPad W510

My power adapter was connected to the ThinkPad W510, a standard PC that takes up significantly less desk space than the ThinkPad W510. The laptop consumes 28 watts of power while it is idle or not in use.

It is already set to a moderate wattage (browser, image processing, office programs, e-mail). And at the most eminent level? My batteries are charging at a rate of 88 watts.

However, the processor’s actual speed varies significantly when doing processor-intensive operations such as video transcoding, particularly when they are performed fast. Thus, if I use the average, it is approximately 39 watts!

In standby mode, this machine consumes only 1.9 watts of power. This machine is currently in a completely relaxed state, producing one and twenty-one watts. What happens if the laptop is taken out of the socket? In standby mode, the AC supply consumes only 0.8 watts.

While the total energy usage is greater when the laptop is not plugged in, it is negligible when the battery is only powering the laptop.

The Smaller Laptop: ThinkPad x100e Power Consumption

The wattage was computed in the context of a highly efficient machine. Additionally, the ThinkPad X100e is offered in a smaller form factor. The combo includes a sluggish processor and a low-power graphics card.

Is it more environmentally friendly? This item has been on continuously throughout the day, and it remains in standby mode while not in use.

Without a connected device, it consumes only 90 watts of power. The less energy-intensive laptops utilise 15 watts when idle. The system achieves 24 watts between medium and high.

When the CPU is fully utilised, this notebook produces 35 watts (i.e. when a video is playing). This machine consumes less energy, which allows me to leave it on all day without worrying about conservation.

How Many Watts Does a Laptop Use When Charging?

You should be able to determine the amount of electricity required to run your laptop using the industry standard of “about 90 Watts per hour.”

Essentially, you must ensure that the laptop’s power cord has not been severed. There will be various resources available to assist you in gathering that type of material.

My 17-inch gaming laptop (which requires a little more energy for web browsing) consumes 180 watts per hour when seen on the right.

To determine your laptop’s battery charging voltage and capacity, check at the charger that came with it.

Battery life reducing factors

The simple line is that your laptop consumes significantly less power than most chargers do while they are operating, which is why knowing the wattage output of your charger does not entirely forecast how long it will take to charge.

It consumes less energy when running on batteries, but even less when charging, according on the charger’s specifications. The chargers for these printers are limited to printing the specified amount of pages: (which is usually around 90 Watts).

Power usage varies between laptops but is highly dependent on how they are used. When not in use, your laptop consumes very little electricity. Internet use, for example, would consume more energy.

The phone is the same way: the more you do on it, the shorter the battery life.

Additional factors that affect your laptop battery lifetime:

Dimensions of the display You’ll need a higher-powered monitor to see a larger image. Laptops consume less power and so have a longer battery life.

1) Internal components

Graphics Cards (particularly those equipped with dedicated GPUs) consume more energy. As you can see, the more hard discs you have, the more power is required to run them.

Additionally, power is drawn by the CPU; however, this varies depending on what you’re doing with your laptop. The CPU has an effect on the amount of energy you consume. When CPU-intensive tasks are completed, your laptop’s fuel consumption can be increased.

2) External peripherals

Anything that is not connected to your laptop, such as a mouse, keyboard, game controller, or monitor, can consume more power. Numerous options are available.

Additionally, unplug any peripherals that are not in use!

3) Laptop Adapter

There is only one way to determine How Many Watts Does a Laptop Charger Use. Each inch laptop includes a power cord, and the power requirements are determined by the display connector on the screen.

The plug on a 15-inch laptop charger draws 65 watts, while the connector on a 17-inch laptop charger draws 90 watts.

Today, your laptop can charge dependent on wattage with these two adapters.

As a result, it’s reasonable to predict that your laptop will consume between 60 and 90 watts of power.

4) Central Information Processing Unit

The CPU is a critical component of any device or laptop’s or system’s operation. In this context, “CPU” refers to the central processing unit. The OS is entirely reliant on the CPU to perform its functions.

With so many various software packages available to optimise the performance of any CPU regardless of the Windows version, the version you use is irrelevant. Our comprehension will grow, but our battery life will suffer as a result. CPU usage has the capability to eat power until the battery dies.

The converter converts energy into watts and powers the laptop. As a result of the increased demand on the CPU, more power will be required.

Additionally, keep in mind that the laptop now weighs more. On the contrary, this is why the device is referred to as an adaptor. It is really helpful because it enables us to take advantage of watts in some instances.

5) Dual video card

If you’re one of the few who use resource-intensive apps, you’re already familiar with the secrets of your smartphone’s battery loss.

A graphics card loaded with powerful software that enables higher resolutions and clarity-enhancing capabilities; they frequently assist in operating and using the apps for which they were intended.

The presence of a graphics card alters the maximum wattage that a battery can deliver, increasing the amount of energy that can be consumed during charging.

Batteries and adapters continue to battle in such conditions, which is why the adapter battery overheats and a laptop fails.

FAQs ― How Many Watts Does a Laptops Charger Use?

How much power does a laptop charger use?

This is a waste of energy. It’s just another vampire. Cell phone chargers consume 0.26 watts of electricity, whereas laptop power bricks consume around 4.42 watts.

Can I use a 90 watt charger on a 65 watt laptop?

You may power the device with either a 90 watt AC adapter or a battery adapter. The assertion is correct; it will aid in the charging of your battery. However, are you aware that you cannot use a 19V adaptor with an 18.5V laptop?

Can I charge my laptop with a lower wattage charger?

Without a doubt. Regardless of the wattage, you can use a lower-wattage charger to avoid throttling your laptop’s output. For instance, charging a laptop with 45 watts of power may result in performance degradation.

Can a 65W charger for 45W laptop?

That is correct. Wattage is the unit of measurement for the amount of power that a charger can deliver. A 45w computer cannot operate at maximum capacity without a 65w power supply, and vice versa.


Using the information on the underside of the laptop, you may determine How Many Watts Does a Laptop Charger Use. Because it is described under “Input,” a crucial characteristic is labelled “Output.” To get the amount of energy consumed, multiply the voltage by the amperage.

While it is required to maintain maximum power consumption, a little increase in power consumption is predicted. As a result, when the notebook is charging. The system will consume up to 70% of the network’s bandwidth. Additionally, it is impossible to accurately calculate the value with a voltmeter.