Work and Power
Calculate work, time, or power using P = W/t. Enter any two values to get the third instantly with interactive charts and step-by-step physics breakdowns for students and engineers.
About This Calculator
The Work and Power Calculator helps you solve physics problems involving work, time, and power using the fundamental relationship P = W / t. Whether you are a student studying mechanics, an engineer analyzing machine performance, or a hobbyist working on a project, enter any two known values and instantly get the third.
In physics, work (measured in joules, J) is the energy transferred when a force moves an object over a distance. Power (measured in watts, W) is the rate at which work is done — one watt equals one joule per second. This calculator uses the standard formula P = W / t for power, W = P × t for work, and t = W / P for time, giving you complete flexibility to solve for any unknown.
How It Works
Simply enter values in any two of the three input fields (Work in joules, Time in seconds, Power in watts). When you click Calculate, the tool determines the missing value using the corresponding physics formula. For example, if you enter Work = 500 J and Time = 25 s, the calculator computes Power = 500 / 25 = 20 W. If you enter Power = 100 W and Time = 30 s, it computes Work = 100 × 30 = 3000 J.
The calculator also provides a visual breakdown with bar and pie charts showing how work, time, and power relate to each other. Use the share feature to bookmark or send your calculation results via a unique URL that preserves your input values.
Frequently Asked Questions
How do you calculate power from work and time?
Power is calculated by dividing work by time using the formula P = W / t. For example, if 100 J of work is done in 5 seconds, the power is 100 / 5 = 20 W.
What is the difference between work and power?
Work is the amount of energy transferred when a force moves an object over a distance, measured in joules (J). Power is the rate at which work is done, measured in watts (W), representing how much work is performed per unit of time.
What units are used for work, time, and power?
Work is measured in joules (J), time in seconds (s), and power in watts (W). One watt equals one joule per second (1 W = 1 J/s). Other common units include kilowatt-hours (kWh) for energy and horsepower (hp) for power.
Can I calculate work if I know power and time?
Yes, work can be calculated by multiplying power by time using the formula W = P × t. For instance, if a 50 W machine runs for 10 seconds, it performs 50 × 10 = 500 J of work.
What is the formula relating work, force, and displacement?
Work equals force multiplied by displacement in the direction of the force: W = F × d × cos(θ), where θ is the angle between the force vector and displacement direction. Work is maximum when force and displacement are aligned (θ = 0°).
How is a watt defined in base SI units?
A watt is defined as one joule per second, which in base SI units equals kg·m²/s³. One watt is the power when one joule of work is done in one second.
Can I use this calculator for electrical power calculations?
This calculator uses the mechanical power formula P = W/t, which applies to any form of energy transfer. For electrical power specifically, you would use P = V×I (voltage times current). However, if you know the electrical work done and time, this calculator works for electrical systems too.