Chemistry
Density and buoyancy, molarity and dilution, and radioactive or any other exponential half-life.
Density Calculator
Density from mass and volume, or mass or volume from density, with the relative density and whether the object floats and how much of it sits below the surface.
Molarity Calculator
Molarity from a mass of solute, its molar mass and the solution volume, the mass or volume needed for a target molarity, and dilutions by C1V1 = C2V2.
Molar Mass Calculator
The molar mass of a chemical formula from IUPAC standard atomic weights, with brackets and hydrates read correctly, the percentage composition by mass, and moles to grams both ways.
Half-Life Calculator
How much of a decaying quantity remains after a time, or the half-life, elapsed time or starting amount, with the decay constant and mean lifetime.
Dilution Calculator
How much stock to dilute, the final volume, or the strength you end up with, by C1V1 = C2V2 in any concentration unit, with the water to add.
Percent Yield Calculator
Percent yield from the actual and theoretical yield, either yield from the other and a percentage, or the theoretical yield from the limiting reactant and the balanced equation.
Buffer pH Calculator
The pH of a buffer from its pKa and the concentrations of weak acid and conjugate base, or the base-to-acid ratio for a target pH, by the Henderson–Hasselbalch equation.
Beer–Lambert Law Calculator
Absorbance from the molar absorption coefficient, path length and concentration by A = εlc, or any one of them from the others, with absorbance and transmittance converted.
Ideal Gas Law Calculator
Solve PV = nRT for pressure, volume, amount of gas or temperature from the other three, in the units you have, with the molar volume.
Grams to Moles Calculator
Convert between grams, moles and number of particles for any chemical formula or molar mass, using IUPAC atomic weights and the exact Avogadro constant.
pH Calculator
pH and pOH from a hydrogen or hydroxide ion concentration, a strong acid or base, or each other, with [H⁺] and [OH⁻], at 25 °C.
Boiling Point at Altitude Calculator
The temperature water boils at for your altitude or air pressure, and how much lower that is than at sea level.
Three calculations that come up again and again in a lab or a classroom. Density is mass over volume, and comparing it with a fluid's density says whether something floats and how much of it sits below the surface: an object at 600 kg/m³ floats in water with 60% of its volume submerged. Molarity is moles of solute per litre of solution, worked out from a mass and a molar mass you enter, with the dilution equation for making a weaker solution from a stock one. Half-life turns any exponential decay into how much is left after a time, how long it takes to fall to a level, or what the half-life must be; the mean lifetime, about 1.44 half-lives, is shown beside it because the two are often confused. No material, compound or drug values are stored.