16 Calculators
Science & Chemistry
Physics and chemistry formulas for force, velocity, momentum, energy, waves, electricity, moles, molarity and dilution.
These calculators work the standard formulas of introductory physics and chemistry: velocity and acceleration, force, energy and power, momentum, waves and frequency, Ohm’s law and torque, and the chemistry of moles, molarity and dilution, density, pH, gases, heat and reactions. Each page names the formula, shows every symbol with its unit, and lets you choose which quantity to solve for.
Physical constants come from the CODATA values published by NIST, and each page quotes the value it uses with its source: standard gravity, 9.80665 m/s², the speed of light, the Avogadro constant and the molar gas constant, all exact, and the vacuum permittivity behind the Coulomb constant. Atomic weights are the IUPAC abridged standard atomic weights. Units are SI throughout the working: a mass in grams is turned into kilograms before it meets an acceleration in metres per second squared, and the page says so, because a unit slip is the most common reason a physics answer is out by a factor of a thousand.
Results are computed in 34-digit decimals and then rounded for display, usually to six significant figures. That is more than most textbook answers keep, so round the result to the significant figures your measurements support.
Start here
- How do I make 500 mL of a 0.1 M solution from a 1 M stock?
- Use the dilution mode of the molarity calculator. It gives the volume of stock to measure and the volume of solvent to add.Molarity Calculator: Mass, Concentration and Dilution (C1V1 = C2V2)
- How fast is a car going after accelerating for 8 seconds?
- Enter the starting speed, the acceleration and the time in the velocity calculator, which uses v = u + at.Velocity Calculator: Final Velocity, Acceleration, Average Speed and Free Fall
- How much heat does it take to boil a pan of water?
- The specific heat calculator works out q = mcΔT from the mass of water and the temperature rise.Specific Heat Calculator (q = mcΔT)
How these calculators fit together
Motion and force
The velocity calculator relates distance, time, speed and acceleration with the constant-acceleration equations and works out free fall. The force calculator applies Newton’s second law and covers weight, friction, tension, centripetal force, buoyancy and Coulomb’s law. The momentum calculator handles linear and angular momentum, and the torque calculator turns a force on a lever arm into a turning effect.
Velocity Calculator: Final Velocity, Acceleration, Average Speed and Free FallForce Calculator: Newton’s Second Law, Friction, Tension, Centripetal, Buoyancy and Coulomb’s LawMomentum Calculator: Linear and Angular MomentumTorque Calculator: Torque from Force, Lever Arm and Angle
Energy, waves and electricity
Kinetic and potential energy, power in watts from volts, amps, ohms or energy, the wave relation between speed, frequency and wavelength, and Ohm’s law for voltage, current, resistance and the resistance of a wire.
Kinetic Energy Calculator (and Potential Energy)Watts Calculator: Power from Volts, Amps, Ohms or EnergyFrequency Calculator: Frequency, Wavelength, Wave Speed and PeriodOhm’s Law Calculator: Voltage, Current, Resistance and Wire Resistance
Chemistry
The grams to moles calculator converts between mass, moles and particles. The molarity calculator gives the mass to weigh out for a solution and applies C1V1 = C2V2 to make a weaker solution from a stock. The rest cover density, pH, the ideal gas law, specific heat, theoretical yield and bond order.
Grams to Moles Calculator (and Moles to Grams)Molarity Calculator: Mass, Concentration and Dilution (C1V1 = C2V2)Density Calculator: Density, Mass and Volume (ρ = m/V)pH Calculator: pH, pOH, Hydrogen and Hydroxide Ion ConcentrationIdeal Gas Law Calculator (PV = nRT)Specific Heat Calculator (q = mcΔT)Theoretical Yield Calculator: Limiting Reactant and Percent YieldBond Order Calculator: Molecular Orbital and Resonance Bond Order
What these tools leave out
- These are the idealised textbook models: no air resistance unless a page includes it, rigid bodies, ideal gases, and solutions dilute enough to behave ideally.
- Nothing here is a safety calculation. Lab work, wiring and load-bearing structures follow their own standards and need a qualified person.
- Constants are the published CODATA values; a course may round them differently, which can change the last digit of an answer.
All Calculators
Works out bond order from the bonding and antibonding electron counts of a molecular orbital diagram, or as a resonance average of shared pairs over bond positions.
Works out density from mass and volume, or mass or volume from density, in metric and customary units, with specific gravity and whether the material floats in water.
Works out a force from Newton's second law, weight, friction, rope tension, centripetal motion, buoyancy or Coulomb's law, with the electric field and potential of a point charge.
Works out frequency, wavelength or wave speed from the other two with v = fλ, and converts between frequency, period and angular frequency, using the exact speed of light.
Converts a mass to moles and moles to a mass using molar masses summed from IUPAC standard atomic weights, and converts between moles and numbers of molecules and atoms.
Solves the ideal gas law for pressure, volume, amount of gas or temperature, converting every common unit to SI and using the exact CODATA molar gas constant.
Works out kinetic energy from mass and speed, gravitational potential energy from height, the speed a kinetic energy implies, and the rotational energy of a spinning body.
Works out the mass of solute for a target molarity, the molarity of a solution from its mass and volume, and the stock and solvent volumes for a dilution.
Works out linear momentum from mass and velocity, or angular momentum from a body's shape, size and rotation speed, with its moment of inertia and kinetic energy.
Solves Ohm's law for voltage, current or resistance with the power and conductance, and works out a wire's resistance and voltage drop from its conductivity, length and diameter.
Converts between pH, pOH, hydrogen ion concentration and hydroxide ion concentration using pH + pOH = pKw, with pKw for pure water from 0 to 100 °C.
Solves q = mcΔT for heat, specific heat capacity, mass or temperature change, converting metric and customary units, with water's 4.184 J/(g·°C) as the default.
Works out the theoretical yield of a product from one or two reactant masses and a balanced equation, identifying the limiting reactant, the leftover excess and the percent yield.
Works out the torque a force produces on a lever arm at any angle, or the force needed to reach a target torque, in newton metres, foot-pounds and inch-pounds.
Works out final velocity, acceleration, average velocity or a free fall's time and impact speed with the constant-acceleration equations and standard gravity.
Works out power in watts from voltage and current, current and resistance, voltage and resistance, or energy over time, and the kilowatt hours used over a period.