Find the work done by a force moving an object over a distance at an angle, in joules, kilowatt-hours and kilocalories, with average power from the time taken.
N
m
deg
s
Results
Calculated
Work done
—
joules (J)
Average power
—
watts (W)
Energy in kWh
—
kilowatt-hours
Energy in kcal
—
kilocalories
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What work means in physics
In physics, work is the energy transferred when a force moves an object. Only the part of the force that points along the motion counts, so pushing a crate straight ahead does more work than pulling it with a rope at an angle. Work is measured in joules: one joule is one newton of force moving an object one meter.
Use this calculator for mechanics homework, for estimating the effort of pushing, lifting or towing, and for turning the result into kilowatt-hours or food calories. Adding the time taken gives the average power.
The formulas
W = F × d × cos θ, where F is the force in N, d the distance in m and θ the angle between force and motion.
P = W / t, the average power in watts.
kWh = W / 3,600,000 and kcal = W / 4,184.
Worked example
A 50 N force pushes a cart 10 m along the direction of motion (angle 0°) in 5 seconds, the default inputs. Work = 50 × 10 × cos 0° = 500 J. Average power = 500 / 5 = 100 W. In other units that is 500 / 3,600,000 = 0.0001389 kWh, or 500 / 4,184 = 0.1195 kcal. Pulling the same cart with a rope at 60° gives 50 × 10 × 0.5 = 250 J.
Common mistakes
Using the wrong angle. The angle is between the force and the direction of motion, not from the vertical or the ground.
Confusing work with force. Holding a heavy object still moves nothing, so the physical work is zero.
Mixing units. Use newtons, meters and seconds; convert pounds-force or feet first.
Frequently Asked Questions
Can work be negative?
Yes. If the force opposes the motion (angle above 90 degrees), the work is negative, such as friction slowing a sliding block.
What is the difference between work and power?
Work is the total energy transferred. Power is how fast it is transferred, work divided by time.
Why is the work zero at 90 degrees?
Because the force is perpendicular to the motion, so none of it acts along the path. cos 90 degrees is 0.
How many joules are in a food calorie?
One kilocalorie (a food Calorie) is 4,184 joules, which is how the kcal result is found.
Practical Guide for Work Calculator - Calculate Work Done by Force
Work Calculator - Calculate Work Done by Force is most useful when the inputs reflect the situation you are actually planning around, not a best-case estimate. Treat the result as a decision aid: it gives you a structured way to compare assumptions, spot outliers, and decide what to verify next. For Physics work, the most important review lens is units, idealized assumptions, boundary conditions, measurement precision, and expected physical scale.
Start with a baseline run using values you can defend. Then change one assumption at a time and watch which output moves the most. If one input dominates the result, spend your verification time there first. If several inputs have similar influence, use a conservative scenario and an optimistic scenario to create a practical range instead of relying on a single exact number.
Before acting on the result, verify the output with dimensional analysis, known reference values, or a second formula when possible. This is especially important when the calculator supports a purchase, project plan, performance target, or operational decision. The calculator can make the math consistent, but the quality of the conclusion still depends on current data, clear units, and assumptions that match your real constraints.
When the output looks surprising, slow down and inspect each input in order. A small change in one high-leverage field can move the final number more than several low-leverage fields combined. For Work Calculator - Calculate Work Done by Force, that means you should first confirm the value with the greatest scale, then confirm the value with the greatest uncertainty, then rerun the calculator with conservative and optimistic assumptions. This sequence turns the calculator from a single answer into a practical decision range.
Review Checklist
Confirm every input uses the unit and time period requested by the calculator.
Run a low, expected, and high scenario so the answer has a useful range.
Check whether rounding or a missing decimal place changes the decision.
Update the calculation whenever the object, medium, force, distance, time, or measurement method changes.