Work Calculator
Work done by a force over a distance, including the angle between them.
What is Work?
In physics, work is done when a force moves an object through a distance: W = Fd cos θ. The cosine term is the part people forget — a force acting at right angles to the motion does no work at all, which is why carrying a suitcase horizontally does no work on it however tiring it feels.
How it works
The angle is between the applied force and the direction of motion, so 0° is a straight push and 180° is friction opposing motion, which gives negative work. Angles may be entered in degrees or radians, and the tool will also solve for the angle itself given the work, force and distance.
- Enter what you know. Every field recalculates as you type — there is no submit button. Leave the quantity you want blank and the page solves for it.
- Read the answer and the working. The result appears above the fold; underneath it is the formula with your numbers substituted, so the arithmetic can be checked rather than trusted.
- Check the units and the size. Units are shown on every value and selectable per field, so a result in kJ, kPa or km/h is converted rather than assumed. Sanity-check the magnitude against a known landmark such as 1 g/cm³ for water.
Examples
A textbook problem with a known answer
Every tool here is checked against standard example problems — the molar mass of C6H12O6 is 180.16 g/mol, and free fall from 20 m takes about 2.02 s at g = 9.8 m/s².
A result you want to reason backwards from
Leave the quantity you already know blank instead: given the final answer, most tools recover the starting value — the mass needed for a target concentration, or the height a fall must have had.
Common mistakes
Forgetting that a formula is only as good as its subscripts
H2O and H2O2 are different compounds. The formula field shows its parse — element by element — so a mis-typed subscript is visible before it reaches the arithmetic.
Mixing units in the middle of a calculation
The most common source of a wrong answer is a value in grams next to a formula expecting kilograms, or Celsius next to a gas constant expecting kelvin. This category converts on the way in and labels what it used.
Frequently asked questions
Why does carrying a bag do no work?
Because the force you exert is upward, against gravity, while the motion is horizontal. At 90° the cosine is zero, so no work is done on the bag in the physics sense — though your muscles still burn energy holding it up.
Can work be negative?
Yes. Friction acting against motion is at 180° to it, and cos 180° = −1, so the work it does is negative. That is energy being removed from the object rather than added to it.
Is work the same as energy?
They are measured in the same unit, the joule, because work is the transfer of energy. The work done on an object shows up as a change in its kinetic or potential energy.