Every physics calculator on Numeros, grouped by topic. Each one states the formula, the SI units it expects, and a worked example — because in physics, getting the units wrong is a more common failure than getting the arithmetic wrong.
Something moving → Velocity or Acceleration. Something falling → Free Fall. Something thrown → Projectile Motion. Something colliding → Momentum. Energy in a system → Kinetic or Potential Energy.
Featured
- Acceleration Calculatoracceleration from a change in velocity over time, using all four kinematic equations.
- Force CalculatorNewton's second law — force, mass or acceleration from the other two.
- Power Calculatorthe rate work is done — from work and time, or force and velocity.
- Projectile Motion Calculatorrange, maximum height and flight time from launch speed and angle.
- Velocity Calculatorvelocity from displacement and time, or solving for either when the third is known.
- Work Calculatorwork done by a force over a distance, including the angle between them.
- Kinetic Energy Calculatorenergy of motion from mass and velocity — and why doubling speed quadruples it.
- Wavelength Calculatorwavelength, frequency and wave speed, for sound, light or any wave.
Mechanics
- Centripetal Force Calculatorthe inward force keeping an object on a circular path, from mass, speed and radius.
- Free Fall Calculatorfall distance, time and impact velocity under gravity, with air resistance neglected.
Energy & momentum
- Gravitational Potential Energy Calculatorstored energy from mass, height and gravity, with the reference point made explicit.
- Impulse & Momentum Calculatorthe change in momentum a force produces over a period, and why contact time matters in safety design.
- Momentum Calculatorlinear momentum from mass and velocity, and conservation across a collision.
Waves & oscillation
- Hooke's Law Calculatorspring force, extension or spring constant, within the elastic limit.
Decay
- Half-Life Calculatorexponential decay over time — remaining quantity, elapsed time or half-life itself.
Related tools
Useful cross-category tools connected to this topic.
- AP Physics Score Calculatorconverts a raw exam score to the 1-5 AP score using released scoring guidelines.
The mistake that costs more marks than any other
In physics, unit errors outnumber arithmetic errors by a wide margin — and they are harder to spot, because the number looks plausible. A velocity in km/h fed into a formula expecting m/s produces an answer wrong by a factor of 3.6, with nothing on the page to suggest anything is amiss.
Every calculator here states the units it expects and the units it returns. The habit worth building is simpler still: write the units alongside every number as you work, and cancel them through the calculation the way you cancel algebraic terms. If the units of your answer are not the units the question asked for, the answer is wrong — and you know it before checking anything else.
Energy should come out in joules (kg·m²/s²), force in newtons (kg·m/s²), power in watts (J/s). If a kinetic energy calculation gives you something in kg·m/s, you used velocity where you needed velocity squared. Dimensional analysis catches most algebra slips before the arithmetic ever runs.
Frequently asked questions
Do these account for air resistance?
No — the Free Fall and Projectile Motion calculators assume a vacuum, which is what introductory physics problems assume too. Real drag depends on shape, surface, air density and velocity in ways that need numerical methods rather than a closed formula. For a dense compact object over a short distance, the idealised result is close. For a feather, or anything at high speed over a long distance, it is not.
What value of gravity do the calculators use?
9.81 m/s² by default, the standard value at Earth's surface. It is editable on the tools where it matters, because gravity varies slightly with latitude and altitude, and because problems set on the Moon or Mars are common in coursework. If your textbook uses 9.8 or 10 for simplicity, change it — the difference is small but your answer should match the method you were taught.
Why does kinetic energy use velocity squared?
Because it follows from the work-energy theorem: integrating force over distance produces ½mv². The practical consequence is worth internalising — doubling a car's speed quadruples its kinetic energy, which is why stopping distance grows so much faster than speed does, and why a crash at 60 is far more than twice as severe as one at 30.
Can I use these for engineering work?
For checking a figure or exploring a relationship, yes. For anything that gets built or specified, no — real engineering needs safety factors, material properties, tolerances and code compliance that no general calculator applies. The engineering tools go further in that direction, but the same limit holds: they inform a decision, they do not make it.
What is the difference between mass and weight here?
Mass is the amount of matter, measured in kilograms, and does not change with location. Weight is the force gravity exerts on that mass, measured in newtons, and does change. Every calculator here takes mass in kilograms. If a problem gives you a weight in newtons, divide by gravity first — entering the newton figure directly is a common and easily missed error.
Are the results exact?
The arithmetic is exact to fifteen significant digits, but that precision is misleading — physics answers are only as good as the model. A free-fall result in a vacuum is exact for a vacuum and approximate for the real world. Round to the significant figures your input justifies; three is usually right for coursework, and reporting more implies a precision the measurement never had.
Other categories
- Math Calculatorsalgebra, geometry, statistics and calculus
- Engineering Calculatorselectrical, mechanical and thermal
- Unit Converterslength, weight, energy, pressure and speed
- Education CalculatorsGPA, grades and study planning