Physics Calculators
Classical mechanics and waves, solved for any variable. Kinematics, Newton’s laws, momentum and impulse, work and energy, pressure, gases and wavelength — with units handled for you.
41 calculators
Most used
- Ohm's Law CalculatorKnow any two of voltage, current, resistance and power? Get the other two, plus conductance and a suggested resistor power rating.
- Projectile Motion CalculatorPlot a projectile's path from launch speed, angle and height, or work backward to the speed or angle that lands it at a chosen distance.
Motion & kinematics 10
- Acceleration CalculatorWork out acceleration three ways — velocity change over time, net force over mass, or distance covered in a known time — with g-force included.
- Average Velocity CalculatorCombine the legs of a trip into one average velocity, see how it differs from average speed, or apply Δx ÷ Δt and (u + v) ÷ 2 directly.
- Displacement (s = ½(u + v)t)Know the starting velocity, the ending velocity and the time? Average the two velocities and multiply by the time to get the displacement.
- Displacement (s = ut + ½at²)Find how far an object moves under constant acceleration from a known starting velocity, or solve the same equation for u, a or t.
- Displacement (s = vt)Multiply a steady velocity by the elapsed time to get displacement, or rearrange s = vt to find the speed or the time a trip takes.
- Final Velocity (v² = u² + 2as)Relate speed, acceleration and distance without knowing the time: final speed after a run-up, distance needed to stop, or speed before a skid.
- Free Fall CalculatorKnow the drop height, the fall time or the impact speed and get the other two, for objects dropped or thrown down on any planet.
- Projectile Motion CalculatorPlot a projectile's path from launch speed, angle and height, or work backward to the speed or angle that lands it at a chosen distance.
- SUVAT CalculatorKnow any three of s, u, v, a and t? Pick that combination and get the other two, with every equation and substitution shown.
- Velocity (v = u + at)Find the velocity after a period of constant acceleration, or work back to the starting velocity, the acceleration or the time it takes.
Force & momentum 9
- Centripetal Force (F = mv²/r)Solve F = mv²/r for force, mass, speed or radius, entering the motion as a linear speed or a rotation rate in rpm.
- Force (F = ma)Apply Newton's second law in any direction: find the net force from mass and acceleration, or the mass or acceleration from the other two.
- Friction (f = μN)Find the friction force, the coefficient μ or the normal force, with the normal force worked out for you on flat ground or a slope.
- Hooke's Law (F = −kx)Find a spring's force, stiffness or stretch from the other two, in either sign convention, along with the elastic energy it stores.
- Impulse (J = FΔt)Find impulse, average force or contact time from J = FΔt, plus the velocity change the impulse gives a mass you enter.
- Impulse-Momentum (FΔt = mΔv)Solve the impulse-momentum theorem for force, contact time, mass, initial or final velocity, with signed velocities for rebounds.
- Momentum (p = mv)Solve p = mv for momentum, mass or velocity, with direction signs, unit conversions and the matching kinetic energy.
- Pressure (P = F/A)Find pressure, force or area from P = F/A, with results in pascals, psi, bar, atmospheres and mmHg.
- Weight (W = mg)Turn a mass into a weight force on Earth or another world, or work back to the mass or the local gravity from a measured weight.
Work & energy 7
- Mass–Energy (E = mc²)Convert any mass into its rest energy with E = mc², or find how much mass corresponds to a given amount of energy.
- Elastic Potential Energy (½kx²)Work out how much energy a stretched or compressed spring stores, or find the spring constant or deflection behind a known energy.
- Potential Energy (U = mgh)Calculate the gravitational potential energy of a raised mass, or work back to the mass, height or gravity behind a known energy.
- Kinetic Energy CalculatorFind kinetic energy, mass or speed from KE = ½mv², with the equivalent drop height and the energy at double the speed.
- Ohm's Law CalculatorKnow any two of voltage, current, resistance and power? Get the other two, plus conductance and a suggested resistor power rating.
- Power (P = W/t)Find power, energy or time from P = W/t, with results in watts, kilowatts, horsepower and BTU per hour.
- Work (W = Fd)Find work, force, displacement or the angle from W = Fd cos θ, with positive, negative and zero work explained.
Matter, gases & waves 4
- Buoyancy (Archimedes)Find the upward force a fluid exerts on a submerged object, then see whether the object sinks or floats, how much it weighs underwater and how deep it rides.
- Density (ρ = m/V)Solve ρ = m/V for density, mass or volume in metric or US units, with specific gravity and a float-or-sink check.
- Ideal Gas Law (PV = nRT)Solve the ideal gas law for pressure, volume, amount of gas or temperature, with unit and kelvin conversions handled for you.
- Wavelength (λ = v/f)Find the wavelength, frequency or speed of a wave in common media, with photon energy and spectrum band for light and radio.
Heat & thermodynamics 2
- Heat Conduction (Fourier's Law)Find the rate of heat flow through a flat layer of material, or the thickness, area, temperature difference or conductivity that gives a target heat loss.
- Specific Heat (Q = mcΔT)Find how much heat it takes to warm or cool a material, or solve Q = mcΔT for the mass, the specific heat or the temperature change.
Gravity & orbits 4
- Escape VelocityCalculate how fast something must go to coast away from a planet, moon or star for good, from its surface or from any height above it.
- Gravitational Force (Newton's Law)Apply Newton's law of universal gravitation to find the force between two masses, or work back to a mass or separation from a known force.
- Orbital Period (Kepler's Third Law)Use Kepler's third law to get the period of an orbit from its size, the size from the period, or the mass of the body being orbited.
- Pendulum PeriodFind a simple pendulum's period from its length, the length for a chosen period, or local gravity from a timed swing, including large release angles.
Optics, sound & electricity 5
- Coulomb's LawFind the attractive or repulsive force between two charges, or work back to a charge or separation, in vacuum, air, water or a custom dielectric.
- Decibels (dB)Combine noise sources, remove background noise, predict how sound fades with distance and convert between decibels, intensity, pressure and ratios.
- Doppler EffectWork out how motion shifts the pitch of sound or the frequency of light, or find how fast a source is moving from the shift you measure.
- Snell's Law (Refraction)Solve n₁ sin θ₁ = n₂ sin θ₂ for an angle or a refractive index, find the critical angle for total internal reflection and see the ray diagram.
- Thin Lens & Mirror EquationFind where a lens or curved mirror forms an image, how big it is and whether it is real or virtual, with a principal-ray diagram for every case.
Guides
- How to Calculate Density (Solids, Liquids and Irregular Objects)Density is mass divided by volume. Learn to measure both for any object, convert density units, rearrange the formula and use density to identify materials.
- How to Calculate Kinetic Energy (and Potential Energy)Kinetic energy is half the mass times the speed squared. Learn the formula, why speed matters so much, how it trades with potential energy, and unit conversions.
- The Kinematic Equations Explained: How to Choose and Use SUVATFour equations describe any motion with constant acceleration. Learn which variable each one leaves out, how to choose, and how to avoid sign errors.
- Ohm's Law Explained: Voltage, Current, Resistance and PowerV = I × R links voltage, current and resistance. Learn to rearrange it, add the power formulas, solve real circuits and know where the law stops applying.