Free online power converter calculators

Power conversion calculator. Convert power units.

Online power converter calculators

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Power converter calculators

Online Power Converter Calculators

What is Power?

You would have heard of the word "power" as not just a purely physical sense but a literal sense as well. However, here we will discuss it in a more scientific, in-depth manner. The term "Power" in physical sciences is defined as a rate at which some amount of work is performed in a particular time interval. As the application of power in the field of science is vast, its units also vary accordingly. Therefore, several times you may need a good power converter to convert power units as per your usage. Let us discuss in detail what is Power and what are its

Sometimes power is defined as the derivative of time concerning work. The derivative means the change in the value function of a certain energy. When work is done at a particular time, the amount of energy and the rate at which it is performed is expressed in terms of power. For example, if you apply a certain force to move a table, the push is considered the force, and when the table is pushed it is the work done. Now, the rate at which this force has helped push the table in a  given time is considered power.

Power is such a variable sort of physical quantity that it has multiple names and units for different other physical quantities. And being a versatile word, power has different literal meanings as well in the context of the English language. In terms of physical energy, however, power is sometimes expressed as a product of velocity and tractive force i.e. the force that is tangent to the ground on which a vehicle is moving with a certain velocity.


The standard symbol of power is "P". When power is expressed in its basic, simplest sense that is how fast work is done in a certain period then it is termed the same and is denoted by the "P" symbol. Sometimes it is interchangeable with work so the work expression that is the product of force and distance can be expressed as power too. In that case, its symbol would be that of work i.e. W.


The basic unit of power is "Watt". In the SI metric system of units, the power is expressed as Joule/sec which is represented by Watt and its symbol is Watt. It is said to be derived from 1 joule per second unit according to the proper definition of power. The name "Watt" was given to the Scottish mechanical engineer James Watt. In 1776, he proposed an improved version of the Newcomen engine with his invention of the steam engine. Watt's improvement of the engine was quite significant and played a major role in the industrial revolution at that time. One watt is defined as the object moving at a constant velocity with one meter per second rate against a fixed force. The rate of work done in this situation will be of one-watt power.


The standard power equation is expressed as power equals the energy/work/force per unit of time. It can be written as follows:


This can also be expressed as:


Here it is also called mechanical power.

The power equation is also written in another way where the relation of power with force and velocity is expressed. It can be represented as:


Here it is denoted as the product of force and velocity.

In older physical science texts, power was also sometimes referred to as "activity".

Power as a Scalar Quantity

In physics, some quantities are considered scalar while others are known as vector quantities. Vector quantities have not only magnitude but also direction. However, the quantities which only have magnitude are scalar. For example, distance is a scalar quantity as it is only measured by its magnitude.

On the other hand, displacement is a vector quantity because it has both magnitude and direction. Similarly, Power is a scalar quantity because it has magnitude but no particular direction. As power is the rate at which work is done it means both are in direct proportion to each other. So, both are scalar quantities.

Power is also defined as the rate of energy transfer which means how fast a body works is the amount of power it has and this can be calculated by the magnitude and involves no particular direction. However, if power is being directed to a surface per unit area, it can be considered a vector called a Poynting vector.

Power Vs Torque

Power, as discussed above, is a scalar quantity with no direction yet Torque is something different. Torque is related to the power of an object such as a motor in terms of its rotational force. This way torque and power can be directly proportional. The torque is measured perpendicular to the moment of the arm always. Therefore, torque is said to be the capacity or tendency of the rotational force to move the body at which it is applied rotationally while power is the rate at which force is exerted to achieve a task.

Torque is commonly measured in pound-feet (lb-ft). It can also be called a twisting force. Consider an example of a moving car, horsepower will be the unit of power that represents the capacity of the force of an engine being transferred to the car's wheels so it moves faster. On the other hand, torque is the twisting force being exerted to rotate the tires. This twisting and pulling force is acting like a tangent to the rotation of the wheels and is created by the piston of the engine moving up and down causing a continuous rotation.

Power and Force

Force is described as a vector quantity having magnitude and direction. It can change the motion of a body and the rate at which it moves as well as its directional speed i.e. its acceleration and its velocity. Derived from the two major equations of velocity and work done, the equation of power as a product of force and velocity is achieved.







When talking about power as a product of force and velocity, the scalar product of force and velocity is used to determine power when an object moves in a particular direction but the velocity is not directed similarly to the force being exerted.

Work, Power, and Energy

These three terms refer to the very important concepts of mechanical physics. Energy is defined as an ability to do work, power is the work being done in unit time, and work is the actual activity being performed. So these three are interrelated. To do work, you require some amount of energy at least. While how fast you perform work in a given time represents your power.

Now if we talk about force coming into this equation, we can understand its role simply by stating that work is done when you push something in a particular direction for it to move. That is why work is denoted by the product of force and displacement.


Work - Energy Principle

Considering the relation between work and energy, a theorem was derived from the second law of motion by Isaac Newton. The work-energy theorem is also called the principle of work and kinetic energy. As the second law of motion states that a body moves in acceleration as much as the constant force is applied to it.



(Force exerted on the body is directly proportional to its acceleration and inversely proportional to its mass.)

Similarly, the work done on the body equals the change in its kinetic or moving energy.

It can be expressed as:

Wnet = ΔKE

Where Wnet = Total work done by an object.

ΔKE= The change in Kinetic Energy from rest to motion. That is the difference between the kinetic energy of an object at the final and the initial stages.

Power Examples from Practical Life

Consider the following simple examples taken from real life to understand the concept of power as a rate at which work is done.

  • A mountain climber is climbing up a high rock using a rope. The amount of height he covers is subject to the energy he has and the rate at which this climbing occurs is his power. So, it can be said that a slow climber has less power than a fast climber.
  • You and your friend are going for a stroll. You start running on the track while your friend is walking. When you run, you are doing work at a higher pace as compared to the work done by your friend who is walking. Therefore, your power is greater than your friend's.
  • Your mother is grinding cardamon an electric spice grinder while you are chopping onions in a manual chopper. The electric motor of the spice grinder or dry mill has more power than the manual chopper and grinds cardamom at a higher rate than the rate at which you are chopping the onion. Your mother would be able to grind more cardamom in a second than the onion that you would be able to chop in the same amount of time.  

The Concept of Simple Machines concerning Power

From a physics perspective, if you push a wall applying some amount of force, you won't be able to move it so no work has been done. Work done requires both a force and movement in an object. Simple Machines provide mechanical assistance while completing work so they transform input work into output work in a changed form. Transforming the energy to some work done requires force and movement.

Six major simple machines can be the foundation for all the machines out there. The efficiency of any machine can be calculated by power input divided by power output. This is called the ratio of power used (input) to the power supplied (output).

Average Power

Mostly the average power is simply called power. However, when instantaneous power is mentioned in the context, the average power is defined in comparison as the total work done or the total amount of energy transferred per unit of time. The unit for average power is generally kilowatt per hour (kW/hr).

P(avg)= total work done / total time

Instantaneous Power

The instantaneous power is simply the power calculated at a given instance or a particular point in time. Where average power is the power consumed averagely over several work cycles in a long period, the instantaneous power is calculated at a given point in a cycle. For example, the speed of the car at a moment in time. It can also be called the limiting value of average power where the time difference approaches zero.

P(inst) = ∆W/ ∆t

Varying Power

Energy resources are used with varying powers and consumption and usage vary over time. For example, the typical energy usage of a house varies from day to day routine. Sometimes it would reach peaks while cooking or heating, etc. while other times it would be barely consumed. So the power can be calculated considering the usage in three steps. Average power, instantaneous power, and peak power.

Peak Power and Duty Cycle

Peak power is the maximum power a device or system reaches in a particular instant or point of time. It can also be defined as the highest value that an instantaneous power could have in a certain energy system. Car engines, for example, can produce higher peak powers than their average powers during normal work cycles. The ratio of average power to peak power can be represented by the duty cycle or power cycle.

The duty cycle expresses the percentage or fraction of time where the power is actively produced in a system.

The duty cycle can be calculated by this equation:

D = PW/T

Where D is the duty cycle, PW is the pulse width, and T represents time.

Radiant Power

Radiant Power is mostly used in radiometry or photometry and quantum mechanics where it is the amount of radiant energy emitted or transmitted per unit of time by a light source. It is also called the radiant flux and is measured in watts.

Acoustic Power

Similar to radiant power used in light physics, acoustic power is mostly used in sound physics or acoustics. It is also called sound power, sound flux, or acoustic flux. It is defined as the sound emitted or transmitted by an audio source per unit of time. For example, the acoustic power of a speaker. The SI unit of sound power in watts (W).

Thermal Power

In thermodynamics, thermal power is the rate at which heat energy is transformed in a thermal system. For example for thermal engines, thermal power describes how fast fuel is converted into heat to perform useful work. The input thermal power is expressed in megawatt thermal (MWt) while the output is considered in megawatt electric (MWe).  

Mechanical Vs Electrical Power

Mechanical power calculates the rate at which work is done through simple machines or manually. While electrical power determines how fast electrical energy is transformed by an electrical device. Mechanical power is generated through mechanical devices whereas electrical power is produced by electrical circuit-operated machines.

Pulsed Power

Pulsed Power is the instant release of power accumulated over a long period in the shortest time interval to increase the rate of instantaneous power. The science behind it suggests that the pulsed Power technology helps improve the mechanism of different systems such as food processing, weaponry, and medical equipment manufacturing.

Most of the time pulsed Power systems store mechanical energy over time and release them in high peaks in microseconds. This helps achieve great instances of power calculated in megawatts that is a million times greater than the average power of the same system.

Power Density

Power density is defined as the amount of power output per unit volume. For example, how fast a device can discharge energy can be referred to as its power density. Modern batteries and mobile devices are being improved because better power densities allow them to process more power within a smaller and more compact space. This enhances the practicality and functionality of a system and reduces cost too. The SI unit of power density is Watt per cubic meter (W/m3).

Power Application

In the field of physics, the application of power is vast and can be categorized by the various subfields of physical science and engineering.

  • Mechanical: As a combination of forces and movement, mechanical power is used in turbines, pulleys, bicycles, brake systems, tractors, belt drive systems, etc.
  • Electrical: Electric power applications can be seen in electrical motors, generators, movers, batteries, escalators, elevators, heaters, air conditioners, automobile engines, refrigerators, etc.
  • Thermal: Thermal power application is mostly seen in thermodynamics where steam engines and turbines are at work. Thermal power usage is also apparent in thermoelectric generators and household appliances such as stoves. Solar thermal power plants are the most important part of the thermoelectric industry today.
  • Radiant: Radiant energy has important applications in infrared technology devices. Cell phones and magnetic motors also utilize radiant power to function. Similarly, microwave technology uses radioactive waves to heat and cook your food. Other than that, x-ray machines, radio transmitters, ray guns, laser devices, etc. involve light to generate power.
  • Acoustic: Acoustic or sound-powered devices are common in our surroundings such as amplifiers and loudspeakers, earphones, microphones, radio and tape recorders, sonographic devices, etc.
  • Atomic: Atomic power plants are the main application area of atomic power. The generation of atomic bombs and nuclear energy systems involve nuclear reactions and atomic power application.

Why is the Power Converter Calculator Important?

Since digitalization occurred, innovation and technology have taken a new meaning in our world. We cannot even spend a day in our life without using a tech gadget one way or the other. Whether you are directly related to science or not, your life revolves around scientific concepts. Physics can be seen in you and around you. Power being one of the main concepts of physics, you would be surprised how frequently you would have to resort to a power converter for easy, quick conversions.

This is why JFT's efficient power converter calculator is designed to convert power units for you accurately. It is important to save time and effort when you are a busy student or industry person. The work that you may be doing in hours can be performed in a fairly quicker way using our power converter.

Sometimes, when you go to buy an electronic device such as a pressing iron or a baking oven, the vendor will tell you the power consumption unit while discussing the machine's specs. Those values may be in watts or megawatts, etc. and you may not be able to grasp fully how to convert it in simple terms for your understanding and what impact would that make on the voltage or current.

Also, different subfields of physics have standardized units of power and the power is differently perceived according to its varying application. Even the units vary according to the region they are being used in.

Similarly, if you are an engine manufacturer, you would be needing conversions from horsepower, which is another standard power unit for engines. At these times, life becomes far easier if you have an automatic power converter calculator at your disposal.

How Our Online Power Converter Calculators Can Help You?

Our power converter is not just for specific industry people. Whether you are a high school student working to finish an urgent assignment involving work, power, and energy or you are a professor in college preparing for a lecture or you are an examiner marking numerical in the assessment papers, you would require quick cross-checking to convert power units. Even if you are not related to the educational field, in practical life also you may need to access our online tool every once in a while.

Maybe you are a refrigerator mechanic or an engine service provider or perhaps just a technical writer for device instruction manuals, in any case, our online power converter calculator can be handy for your everyday calculations. From horsepower to Watts and from watts to refrigeration tons, perform precise conversions for you with zero chances of error.

How does Our Online Power Converter Calculators work?

Gone are the days of tedious, manual computations with an outdated, electronic calculator. Today is the era of digital innovation and embedded online calculators. JFT's special purpose conversion calculators work wonders in saving your time, effort, and energy. You don't have to research and put in any working formula to convert power units for your conversions. You just have to enter your value in the unit field of your choice and the power converter will calculate accurate values for you instantly.

Our developers have worked hard at the back end to provide you with an easy-to-use and navigable interface. This way the conversion becomes a matter of seconds at the front end. As laymen, many people are not aware of complex background information about scientific concepts and terminologies. For this reason, an automatic power converter calculator lets them choose the easy way out without the hassle of going through even the basics. Just entering the value to convert and pressing convert gets the task done at lightning speed with error-free results.

Different Power Measuring Units and their Symbols

Some important power units used commonly in the industry are listed below. Each of them has a separate application and is used for certain electronic devices.

  • Watt (W)
  • Kilowatt (kW)
  • Megawatt (MW)
  • Milliwatts (mW)
  • Refrigeration Tons (TR)
  • British Thermal Unit (BTU)
  • Horsepower (hp)
  • Decibel-Milliwatts (dBm)
  • Decibel-Watt (dBW)
  • Gigawatts (GW)

How to Convert Power Units from BTU/hr to kilowatts (kW)?

One BTU/hr equals 0.000293 kW. Simply, multiply the value of power in BTU/hr by 0.000293 to get the power value in kW.

For example, convert 30 BTU/hr to kW.

P(kW) = P(BTU/hr) × 0.000293

P(kW) = 30 × 0.000293

P(kW) = 0.00879 kilowatts

Access our power converter to convert power units from BTU/hr to kW here.

How to Convert Power Units from BTU/hr to Watts?

One BTU/hr equals 0.293 watts. To convert power units from BTU to Watts, just multiply the value in BTU by 0.293.

For example, convert 30 BTU/hr to Watts.

P(W) = P(BTU/hr) × 0.293

P(W) = 30 × 0.293

P(W) = 8.79 watts

For quick and easy conversion from BTU/hr to Watts use this link.

How to Convert Power Units from BTU/hr to Refrigeration Tons?

Refrigeration tons represent the heat extraction capacity of a cooling device. 1 ton of refrigeration or TR approximately equals 12000 BTU (British Thermal Unit) and 3.516 kW.

To convert power units from TR to BTU, divide the power value in BTU by 12000.

For example, convert 60000 BTU to TR.

P(TR) = P(BTU/hr)/12000

P(TR) = 60000/12000

P(TR) = 5 TR

By using our digital power converter calculator here you can easily convert power values from BTU to refrigeration tons.

How to Convert Power Units from Horsepower to kilowatts?

To convert from electrical or mechanical horsepower to kilowatts, remember that 1 hp = 0.745 kW. So, just multiply 0.745 by the value i. Horsepower.

P(kW) = P(hp) × 0.745

For example, 30 hp to kW will be:

P(kW) = 30 × 0.745

P(kW) = 22.3 kW

To convert from horsepower to kilowatts automatically use our online tool here.

How to Convert Power Units from Horsepower to Watts?

Horsepower has three main types. Mechanical, electrical, and metric horsepower.

1 mechanical Horsepower equals 745.699 watts. By following this equation we can convert power units from horsepower to Watts easily. Just multiply the power value in horsepower by 745.699.

For example, convert 10 hp to Watts:

P(W) = 10 × 745.699

P(W) = 7456.99 watts

1 electrical horsepower equals 746 watts.

P(W) = 10 × 746

P(W) = 7460 watts

1 metric horsepower equals 735.498 watts.

P(W) = 10 × 735.498

P(W) = 7354.98 watts

Access our horsepower-to-Watts power converter here for quicker and more accurate, digital conversions.

How to Convert Power Units from Gigawatts to Watts?

To convert power units from Gigawatts to Watts, understand that. 1 gigawatt equals 10 raised to power 9 watts.

1 GW = 109 watts or 1000000000


1 W = P(GW) × 10-9 or 1/1000000000

So, for instance, 20 GW will be equal to:

P(W) = 20 / 1000000000

P(W) = 20000000000 watts

To convert from Gigawatts to Watts online, use our power converter here.

How to Convert Power Units from Kilowatts to BTU/hr?

One kW equals 3412.142 BTU/hr so you have to multiply the power value in kW by 3412.142 to get the power value BTU/hr.

For example, convert 5 kW to BTU/hr.

P(BTU/hr) = P(kW) × 3412.142

P(BTU/hr) = 5 × 3412.142

P(BTU/hr) = 17060.71 BTU/hr

Click this link for a kilowatt to BTU/hr online power converter.

How to Convert Power Units from Kilowatts to BHP?

BHP stands for the brake horsepower. One mechanical BHP equals 0.745699 watts. To convert power units from kW to BHP just divide the value in kW by 0.745699 to get the power value in BHP.

For example, convert 100 kW to BHP.

P(BHP) = P(kW) / 0.745699

P(BHP) = 100 / 0.745699

P(BHP) = 134.102 BHP

By using our online kW to BHP power converter calculator here you can get the results faster.

How to Convert Power Units from Kilowatts to Milliwatts?

As one kilowatt equals 1000000 milliwatts, multiply the value in kW by 1000000 to get the power value in mW.

For example, convert 1.5 kW to mW.

P(mW) = P(kW) × 1000000

P(mW) = 1.5 × 1000000

P(mW) = 1500000 Milliwatts

However, to save time and energy, you can just convert power units automatically from kW to mW by using our power conversion tool here.

How to Convert Power Units from Kilowatts to Megawatts?

To convert kilowatts to megawatts, consider this equation:

1 MW = 1000 kW

So, 1 kW = 0.001 MW

By dividing the power value in kW by 1000 we will get the power value in MW. For example, converting 30 kW to MW:

P(MW) = 30/1000

P(MW) = 0.03 Megawatts.

Use Our online kilowatts to megawatts power converter here.

How to Convert Power Units from dBm to Milliwatts?

To convert power units from dBm to mW consider the following equation:

P(mW) = 1 mW × 10P(dBm)/10


P(mW) = power in Milliwatts

P(dBm) = power in Decibel-milliwatts

For example, to convert 13 dBm to Milliwatts, enter the value in the formula above:

P(mW) = 1 mW × 1013/10

P(mW) = 1 mW × 101.3

P(mW) = 1 mW × 19.95

P(mW) = 19.95 Milliwatts

For automatic power conversion from dBm to Milliwatts, click here.

How to Convert Power Units from dBm to Watts?

To convert power units from dBm to Watts consider the following expression:

P (W) = 1 W × 10P(dBm)/10/1000


P(W) = power in watt

P(dBm) = power in Decibel-milliwatts

For example, to convert 50 dBm to Watts enter the value in the formula above.

P(W) = 1 W × 1050/10/1000

P(W) = 1 W × 105/1000

P(W) = 100 W

For easy, fast conversion from dBm to Watts, just click this link to access our power converter online.

How to Use Our Online Power Converter Calculators?

Power conversion was never easier before the advent of technology. Now, JFT's online conversion tools have taken the digital world by storm. Our online power converter is especially a treat to use. With so many complex manual methods and working formulas to convert power units, a layman can become easily confused. However, by accessing our power converter calculator you can put your conversion dilemmas aside and use this simple method to get your converted values with impressive speed and accuracy.

Follow these simple steps to use our power converter:

  • Choose the conversion combination in which you want to convert power units.
  • Click on the associated link with it.
  • A conversion interface will appear. The box will have fields corresponding to the units you want to convert.
  • Enter the value to convert power units.
  • Press the "convert"
  • Your value will be converted to the power unit of your choice.
  • Press the "reset" button to start anew.

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