Physics Calculators

Shadow Length Calculator

Calculate the length of a shadow cast by any object based on its height and the sun's elevation angle. Works in meters or feet.

Entropy Change Calculator (Thermodynamics)

Calculate entropy change (ΔS) for chemical and physical processes using the fundamental thermodynamic relationship. Find entropy from heat transfer, temperature, and reactions.

Nuclear Binding Energy Calculator

Calculate the nuclear binding energy and mass defect of an atomic nucleus from proton and neutron counts using Einstein mass-energy equivalence.

Acceleration from Force Calculator

Calculate acceleration, force, or mass using Newton's Second Law (F = ma). Solve for any of the three variables.

Angular Momentum Calculator

Calculate angular momentum of a rotating object using mass, velocity, and radius, or moment of inertia and angular velocity.

Brachistochrone Trajectory Calculator

Calculate interplanetary travel time using the flip-and-burn maneuver: accelerate to the midpoint, flip, then decelerate. Enter origin, destination, and thrust level.

Buoyancy Force Calculator

Calculate the buoyancy (upward) force on any object submerged in a fluid. Uses Archimedes Principle. Supports water, seawater, oil, and custom fluids.

Centrifugal Force Calculator

Calculate centrifugal (centripetal) force for rotating objects. Enter mass, velocity, and radius to find the outward force in Newtons and other units.

Coulomb's Force Calculator

Calculate the electrostatic force between two charged particles using Coulomb's Law. Enter charge and distance to find the force.

Decibel Distance Calculator

Calculate sound level at any distance using the inverse square law. Convert dB at one distance to dB at another.

Doppler Effect Frequency Calculator

Calculate the observed frequency shift due to the Doppler effect. Works for sound, light, and radar applications with source or observer motion.

Drag Coefficient Calculator

Calculate aerodynamic drag force on objects moving through air or fluid. Enter velocity, area, and drag coefficient (Cd) to find drag force in Newtons and pounds-force.

Electric Field Strength Calculator

Calculate electric field strength from a point charge or between parallel plates using Coulomb law.

Electrical Conductivity Calculator

Calculate electrical conductivity, resistivity, resistance, or conductance of a material or wire using standard formulas.

Heat Capacity Calculator

Calculate the heat energy needed to raise or lower the temperature of any substance using specific heat capacity values.

Kinetic Energy Calculator

Calculate the kinetic energy of any moving object. Enter mass and velocity to get energy in Joules, kilojoules, calories, and BTUs. Supports metric and imperial units.

Lens Power (Diopter) Calculator

Calculate lens power in diopters from focal length, or find focal length from diopter value. Covers eyeglasses and optics.

Light Intensity (Inverse Square Law) Calculator

Calculate how light intensity changes with distance using the inverse square law. Useful for photography, lighting design, and physics.

Magnetic Force Calculator

Calculate the magnetic force on a moving charge or current-carrying conductor using the Lorentz force law.

Projectile Range Calculator

Calculate the range, maximum height, and time of flight of a projectile using launch speed and angle. Supports metric and imperial units.

Radioactive Half-Life Remaining Calculator

Calculate how much of a radioactive substance remains after a given time. Enter initial amount, half-life period, and elapsed time to get remaining quantity and decay percentage.

Refraction Index Calculator

Calculate the angle of refraction using Snell's Law. Find the refractive index or refracted angle when light passes between two materials.

Relativistic Rocket Calculator

Calculate interstellar travel time with time dilation. Uses Einstein's special relativity for a constantly-accelerating rocket — enter distance in light-years and thrust level.

Specific Heat Calculator

Calculate heat energy absorbed or released, temperature change, or specific heat capacity using Q = mcΔT. Supports metric and imperial units.

Static Electricity Voltage Calculator

Estimate the voltage of a static electric discharge based on material type, humidity, and activity. Understand why static shocks happen and how to prevent them.

Stefan-Boltzmann Radiation Calculator

Calculate thermal radiation power emitted by an object using the Stefan-Boltzmann law. Find heat radiated by temperature and surface area.

Thermal Conductivity Heat Flow Calculator

Calculate heat flow rate through a material using thermal conductivity, thickness, area, and temperature difference. Useful for insulation and building design.

Time Dilation Calculator

Calculate relativistic time dilation at any speed. Enter velocity in km/s, mph, or as a percentage of the speed of light and see how time slows for a moving observer.

Wave Speed Calculator

Calculate wave speed, frequency, or wavelength using the wave equation. Works for sound, light, and water waves.

Friction Force Calculator

Calculate static and kinetic friction force. Enter mass, angle, and friction coefficient to find friction, normal force, and net force.

Snell's Law Calculator

Calculate light refraction angles using Snell's Law. Enter refractive indices and incident angle to find refraction angle and critical angle.

Spring Force Calculator (Hooke's Law)

Calculate spring force, displacement, or spring constant using Hooke's Law. Includes potential energy and oscillation frequency.

Thin Lens Equation Calculator

Calculate focal length, object distance, or image distance using the thin lens equation. Supports converging and diverging lenses.

Battery Bank Calculator

Size a battery bank for off-grid solar systems. Calculate battery capacity needed based on daily energy usage and backup days.

Centrifuge RPM to RCF Converter

Convert between centrifuge RPM and RCF (g-force). Calculate relative centrifugal force from rotor radius and speed.

Doppler Shift Calculator

Calculate the Doppler effect for sound and light. Find the observed frequency when source or observer is moving.

Earthquake Distance Calculator

Estimate earthquake distance from P-wave and S-wave arrival time difference. Used in basic seismology.

Focal Length Equivalent Calculator

Convert camera focal lengths between sensor sizes including full frame, APS-C, Micro Four Thirds, and more.

Half-Life Calculator

Calculate radioactive or chemical half-life decay. Find remaining quantity, elapsed time, or half-life period from known values.

Noise Level and Safe Exposure Calculator

Compare decibel levels of common sounds and calculate maximum safe exposure time at any noise level.

Radiation Dose Comparison Calculator

Compare radiation exposure levels in millisieverts. See how common sources compare to annual background radiation.

Radioactive Decay (Half-Life) Calculator

Calculate radioactive decay, remaining material, and activity after a given time. Supports common isotopes with known half-lives.

Seismic Intensity Calculator

Convert between earthquake magnitude scales and estimate ground motion intensity.

Sound Wavelength Calculator

Calculate the wavelength of a sound wave from its frequency and the speed of sound in air or other media.

Terminal Velocity Calculator

Calculate the terminal velocity of a falling object based on mass, drag coefficient, cross-sectional area, and air density.

Battery Energy Calculator

Calculate battery energy in Wh and kWh from voltage and amp-hours. Estimate runtime at a given load.

Electrical Power Calculator (Ohm's Law + Power Wheel)

Enter any two of Voltage, Current, Resistance, or Power and calculate the other two using Ohm's Law and the power formula.

Electricity Bill Estimator

Estimate your monthly electricity bill based on appliance usage and your electricity rate.

Magnetic Field Calculator

Calculate the magnetic field strength around a straight current-carrying wire using the Biot-Savart law (simplified).

Projectile Motion Calculator

Calculate maximum height, range, and time of flight for a projectile. Enter launch velocity and angle to see the full trajectory.

Specific Gravity Calculator

Calculate specific gravity from substance and reference densities. Instantly tells you if the material will float or sink.

Static Water Pressure Calculator

Calculate water pressure at the bottom of a column based on elevation difference. Supports PSI and bar units.

Torque Calculator

Calculate torque from force and distance, or solve for any missing variable. Enter two values to find the third.

Voltage Drop Calculator

Calculate voltage drop in electrical wiring based on wire gauge, length, and current.

Wavelength to Color Calculator

Convert a light wavelength in nanometers to its visible color name, approximate RGB value, and frequency in THz.

Wire Resistance Calculator

Calculate the electrical resistance of a wire based on material, length, and gauge. Supports imperial and metric units.

Acceleration Calculator

Calculate acceleration from initial velocity, final velocity, and time. Also computes distance traveled during acceleration.

Buoyancy Calculator

Calculate buoyant force and whether an object will float or sink. Enter object volume, object density, and fluid density.

Carbon-14 Dating Calculator

Estimate the age of an organic sample based on the remaining percentage of Carbon-14.

Centripetal Force Calculator

Calculate centripetal force and acceleration for circular motion. Enter mass, velocity, and radius to find the force keeping an object in its path.

Coulomb's Law Calculator

Calculate the electric force between two charged particles using Coulomb's Law. Enter charges and distance to find the force.

Decibel Calculator

Calculate the decibel (dB) difference between two power or intensity levels, or convert dB to intensity ratio.

Density Calculator

Calculate density, mass, or volume using the density formula. Essential for physics and chemistry.

Drug Half-Life Calculator

Calculate the remaining dose of a medication in your system based on initial dose, half-life, and time elapsed.

Earthquake Energy Calculator

Enter an earthquake magnitude and see the energy released in joules and TNT equivalent. Understand the power behind Richter scale numbers.

Electricity Cost / kWh Calculator

Calculate how much electricity an appliance uses per month and what it costs. Enter watts, hours per day, and your electricity rate.

Escape Velocity Calculator

Calculate the escape velocity for any celestial body from its mass and radius. Includes presets for Earth, Moon, and Mars.

Force Calculator (Newton's Second Law)

Calculate force, mass, or acceleration using F = ma. Essential for physics problems.

Fuel Energy Content Calculator

Calculate the energy content of gasoline, diesel, natural gas, or propane in BTU and kilojoules. Compare fuel types by energy density.

Gravity / Free Fall Calculator

Calculate free fall time and impact velocity from height, or find height from fall time. Supports both metric and imperial units.

Heat Transfer Calculator (Q = mcΔT)

Calculate heat energy transferred using mass, specific heat capacity, and temperature change. Supports joules, calories, and BTU output.

Kinetic Energy Calculator

Calculate kinetic energy from mass and velocity using KE = ½mv². Supports SI (Joules) and Imperial (ft·lbf) units.

Lightning Distance Calculator

Calculate how far away lightning struck based on the seconds between the flash and thunder.

Momentum Calculator

Calculate momentum from mass and velocity, or use the collision calculator to find velocities after elastic and inelastic collisions.

Noise Reduction Calculator

Calculate how much a noise barrier reduces sound levels. Enter source decibels, barrier NRC rating, and distance for the reduced dB level.

Ohm's Law Calculator

Calculate voltage, current, or resistance using Ohm's Law. Essential for electronics and electrical engineering.

Pendulum Calculator

Calculate the period and frequency of a simple pendulum based on its length.

Pipe Volume Calculator

Calculate the volume of water or fluid inside a pipe by entering diameter and length. Supports inches, feet, centimeters, and meters.

Radioactive Decay Calculator

Calculate the remaining amount of a radioactive substance after a given time using the half-life decay formula.

Reynolds Number Calculator

Calculate the Reynolds number to determine if fluid flow is laminar or turbulent based on velocity, diameter, and viscosity.

Speed of Sound Calculator

Calculate the speed of sound in air, water, or steel at any temperature. Includes unit conversion between m/s, ft/s, mph, and km/h.

Speed, Distance & Time Calculator

Calculate speed, distance, or time given the other two values. Supports multiple units.

Thermal Expansion Calculator

Calculate how much a material expands or contracts with temperature changes. Supports steel, aluminum, copper, and wood.

Thin Lens Equation Calculator

Solve the thin lens equation 1/f = 1/do + 1/di. Enter any two of focal length, object distance, or image distance to find the third.

Time Dilation Calculator

Calculate relativistic time dilation and length contraction from Einstein's special relativity. Enter velocity as a percentage of the speed of light.

Water Flow Rate Calculator

Calculate water flow rate through a pipe based on diameter, pressure, and pipe length. Results in GPM and LPM.

Wavelength Calculator

Calculate wavelength from frequency and wave speed. Supports light (speed of light) and sound waves. Shows results in meters, nanometers, and centimeters.