Calculate mechanical power, representing the rate at which work is done over time.
Average Power (P)
10W
How is this calculated?
Power Formula: P = W / t
P = 100 J / 10 s
P = 10 W
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About the Power Calculator
In physics, power measures how quickly work gets done. While a person and a forklift can both do the same amount of work lifting a heavy box, the forklift does it much faster—meaning it generates more power.
Mathematical Formula & Logic
Average Power (Work over Time)
P = W / t
- P = Power (W)
- W = Work (J)
- t = Time (s)
Instantaneous Power (Force and Velocity)
P = F * v
- P = Power (W)
- F = Force (N)
- v = Velocity (m/s)
Step-by-Step Example
If you do 500 Joules of work in 10 seconds, your average power output is 500 / 10 = 50 Watts.
A motor doing 5,000 Joules of work in 2 seconds generates 2,500 Watts of power.
Reference Data & Values
work
time
power
100
10
10
5000
2.5
2000
10
1000
0.01
0
50
0
-500
10
-50
Frequently Asked Questions
The primary formula for mechanical power is P = W / t, where P is power, W is work, and t is time.
The standard SI unit for power is the Watt (W). One Watt equals one Joule of work done per second (J/s).
Work is the total amount of energy transferred, while power is how fast that energy is transferred. Walking or running up the stairs requires the same work, but running requires more power.
If you know the force applied to an object and its constant velocity, you can calculate instantaneous power using P = F × v.
Horsepower (hp) is an older imperial unit of power. One mechanical horsepower is exactly equivalent to 745.7 Watts.
Yes, if the work done is negative (like friction slowing down a car), the calculated power is negative, meaning energy is being removed from the system.
Because power is a rate. Doing a large amount of work over a whole day requires very little power, but doing that same work in one second requires a massive burst of power.
The concept (energy over time) is the same, but in circuits, electrical power is usually calculated using voltage and current: P = V × I.