# Work & Power Calculator

Calculate work and power using W = Fd and P = W/t. Enter force, distance, and time to get results in Joules, Watts, and horsepower.

## What this calculates

Work and power are fundamental concepts in physics that describe energy transfer. Work is done when a force moves an object over a distance (W = Fd), and power is the rate at which that work is performed (P = W/t). This calculator computes both, giving you results in standard SI units as well as practical units like kilojoules and horsepower.

## Inputs

- **Force** (N) — min 0
- **Distance** (m) — min 0
- **Time** (s) — min 0 — Time over which the work is done (for power calculation)

## Outputs

- **Work** (J) — Work done in Joules
- **Work** (kJ) — Work done in kilojoules
- **Power** (W) — Power in Watts
- **Power** (hp) — Power in horsepower (1 hp = 745.7 W)

## Details

In physics, work has a precise definition: it is the energy transferred when a force moves an object through a displacement. The formula assumes the force is applied in the direction of motion.

  - W = F × d — Work (Joules) = Force (Newtons) × Distance (meters)

  - P = W / t — Power (Watts) = Work (Joules) / Time (seconds)

For forces applied at an angle θ to the direction of motion, work becomes W = Fd·cos(θ). This calculator assumes the force is parallel to the displacement (θ = 0).

Unit conversions: 1 Joule = 1 N·m. 1 Watt = 1 J/s. 1 horsepower = 745.7 Watts. 1 kilowatt-hour (kWh) = 3,600,000 J.

Practical examples: Lifting a 10 kg object 2 meters requires about 196 J of work (against gravity). A 75 kg person climbing stairs at 1 m/s produces about 735 W of power (roughly 1 hp).

## Frequently Asked Questions

**Q: What is the difference between work and energy?**

A: Work is the process of transferring energy by applying a force over a distance. Energy is the capacity to do work. When work is done on an object, its energy changes by the amount of work done.

**Q: What is the difference between work and power?**

A: Work measures the total energy transferred (in Joules). Power measures how quickly that energy is transferred (in Watts = Joules per second). Two people can do the same work, but the one who does it faster has more power.

**Q: What is a horsepower?**

A: One mechanical horsepower equals 745.7 Watts. It was originally defined by James Watt as the power of a horse lifting 550 pounds by one foot in one second.

**Q: Can work be negative?**

A: Yes. When the force opposes the direction of motion (like friction), the work done by that force is negative. This calculator assumes positive force in the direction of motion.

**Q: Why is time needed for power but not for work?**

A: Work only depends on force and distance. Power is the rate of doing work, so it also requires knowing how long the work took. The same amount of work done in less time requires more power.

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Source: https://vastcalc.com/calculators/physics/work-power
Category: Physics
Last updated: 2026-04-21