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Physics Calculators

50 free calculators — type in numbers and get the answer with the working shown. Every calculation runs in your browser; nothing is sent anywhere.

⚙️ Classical Mechanics

Forces, energy, momentum and motion.

Banked Curve Calculator

Find the ideal banking angle for a curved road, or the speed a vehicle can hold on a banked bend without any friction helping it.

tan θ = v² ÷ (r × g)

Buoyancy Calculator

Find the upward buoyant force on a submerged object from the fluid density and the volume of fluid that it displaces when immersed.

F_b = ρ × V × g

Centripetal Force Calculator

Find the inward force needed to keep an object moving in a circle, or the speed it gives for a known inward force around the circle.

F_c = m × v² ÷ r

Circular Motion Calculator

Find centripetal acceleration, angular speed and orbital period for an object moving steadily around a circular path at constant speed.

a = v² ÷ r

Escape Velocity Calculator

Find the speed an object needs to escape a planet's gravity forever, worked out from the planet's mass and radius alone.

v = √(2 × G × M ÷ r)

Gravitational Field Calculator

Find the strength of gravity at a distance from a planet or star, or the mass that produces a given field strength at that point.

g = G × M ÷ r²

Gravitational Potential Energy Calculator

Find the stored energy of an object raised above the ground, or the height or mass behind a known amount of energy held at that height.

PE = m × g × h

Hooke's Law Calculator

Find the force needed to stretch or compress a spring, or its extension or spring constant from a known applied force within its elastic limit.

F = k × x

Impulse and Momentum Calculator

Find the impulse from a force acting over time, or the change in momentum from a mass and its change in velocity during the push.

J = F × Δt = Δp

Kinetic Energy Calculator

Find the kinetic energy of a moving object, or work backwards to its speed or mass from a known amount of energy stored in its motion.

KE = ½ × m × v²

Momentum Calculator

Find the momentum of a moving object, or work out its velocity or mass from a known value of momentum for the object in motion.

p = m × v

Net Force Calculator

Add the forces acting on an object to get the net force, then find the acceleration that net force produces in the object.

F_net = F₁ + F₂

Newton's Second Law Calculator

Find the force, mass or acceleration in Newton's second law, the link between a push and the motion that it causes in an object.

F = m × a

Pendulum Period Calculator

Find the swing period of a simple pendulum from its length and gravity, or the length that gives a chosen period of swing.

T = 2π × √(L ÷ g)

Torque Calculator

Find the turning effect of a force applied at a distance from a pivot, or the force behind a known amount of torque on a lever.

τ = r × F × sin θ

Vector Addition Calculator

Find the size and direction of a vector from its horizontal and vertical components, or combine two parts together into one resultant vector.

R = √(A_x² + A_y²)

Work and Power Calculator

Find the work done by a force pushing an object along a distance, or the power when that work is done over a known time.

W = F × d × cos θ

Young's Modulus Calculator

Find a material's stiffness from a stretch test, or the stretch a known force and modulus will produce in a sample of that material.

E = F × L ÷ (A × ΔL)

📐 Kinematics

Describing motion: velocity, acceleration and trajectories.

Free Fall Calculator

Find the speed, fall time or drop height of an object falling freely under gravity with no air resistance slowing it down on the way.

v = √(2 × g × h)

Projectile Motion Calculator

Work out the range, peak height and flight time of a projectile launched at an angle from level ground, ignoring air resistance.

R = v₀² sin(2θ) ÷ g

Relative Velocity Calculator

Find how fast one object moves as seen from another, for motion along the same straight line at constant speeds in either direction.

v_rel = v₁ − v₂

SUVAT Motion Calculator

Solve constant-acceleration motion problems for final velocity and displacement using the standard SUVAT equations of motion.

v = u + a × t

Terminal Velocity Calculator

Find the steady falling speed where air resistance balances weight, or the mass that falls at a given terminal speed through the air.

v_t = √(2 × m × g ÷ (ρ × A × C_d))

⚡ Electromagnetism

Charge, current, fields, circuits and magnetism.

Capacitor Energy Calculator

Find the energy stored in a charged capacitor, or work out its voltage or capacitance from the amount of energy stored in it.

U = ½ × C × V²

Coulomb's Law Calculator

Find the electrostatic force between two point charges, or the separation that gives a chosen force between the two charges.

F = k × q₁ × q₂ ÷ r²

Electric Current Calculator

Find the current in a wire from the charge that flows and the time it takes, or work out the charge or time instead for the same wire.

I = Q ÷ t

Electric Field Calculator

Find the electric field strength around a point charge, or the force it exerts on a small test charge placed nearby in the field.

E = k × Q ÷ r²

Electrical Power Calculator

Find the power in a circuit from voltage and current, or from current and resistance, or voltage and resistance instead in the same circuit.

P = V × I

Faraday's Law Calculator

Find the voltage induced in a coil by a changing magnetic flux, or the flux change through the coil that a given induced voltage implies.

ε = N × ΔΦ ÷ Δt

Magnetic Force Calculator

Find the magnetic force on a moving charge or on a current-carrying wire in a magnetic field at any chosen angle to the field lines.

F = q × v × B × sin θ

Ohm's Law Calculator

Work out voltage, current or resistance in a simple electric circuit from the direct link between the three quantities involved.

V = I × R

Resistor Combination Calculator

Find the total resistance of two resistors wired in series or in parallel, and compare the two different arrangements side by side.

R_series = R₁ + R₂

🔥 Thermodynamics

Heat, temperature, energy and entropy.

First Law of Thermodynamics Calculator

Find the change in a system's internal energy from the heat added to it and the work it does on its surroundings during the process.

ΔU = Q − W

Gas Laws Calculator

Use the combined gas law to find a gas's new pressure, volume or temperature after one of those quantities has changed in a sealed container.

P₁V₁ ÷ T₁ = P₂V₂ ÷ T₂

Ideal Gas Law Calculator

Find the pressure, volume or amount of an ideal gas from the other three quantities using PV equals nRT for gases at a given temperature.

P × V = n × R × T

Specific Heat Calculator

Find the heat needed to warm a substance, or work out its specific heat or temperature change from the heat supplied to the substance.

Q = m × c × ΔT

Thermal Expansion Calculator

Find how much a solid rod lengthens when heated, or the original length behind a measured expansion of the rod after warming.

ΔL = α × L₀ × ΔT

🌊 Waves & Optics

Waves, sound, light, lenses and interference.

Doppler Effect Calculator

Find the pitch a listener hears from a moving sound source as it approaches them or moves away from them in the air at a steady speed.

f′ = f × v ÷ (v − v_s)

Lens and Mirror Calculator

Find image distance, focal length or magnification for a thin lens or mirror from the object distance in front of it using the lens equation.

1 ÷ f = 1 ÷ d_obj + 1 ÷ d_img

Refractive Index Calculator

Find a material's refractive index from the speed of light inside it, or the light speed inside a material of known index.

n = c ÷ v

Snell's Law Calculator

Work out how a light ray bends when it crosses between two materials, or find the unknown refractive index of a material.

n₁ sin θ₁ = n₂ sin θ₂

Speed of Light / Frequency–Wavelength Calculator

Find the frequency or wavelength of light from the other one, using the speed of light in a vacuum as the link between them.

c = λ × f

Wave Interference Calculator

Find where bright fringes appear in a double-slit pattern, or the wavelength behind a measured fringe position on screen in the pattern.

y = m × λ × L ÷ d

Wave Speed Calculator

Find a wave's speed, frequency or wavelength from the other two quantities, using the wave equation v equals f times lambda.

v = f × λ

⚛️ Modern Physics

Quantum mechanics, relativity, atoms and beyond.