Chemistry Calculators
Last updated: October 2026
Molecular Weight Calculator
Compute the molecular weight (molar mass, g/mol) of a carbon-hydrogen-oxygen-nitrogen compound from its atom counts, with natural-abundance, monoisotopic, ¹³C-labelled or deuterated masses.
Solution Dilution Calculator
Find the concentration of a solution after dilution with C₁V₁ = C₂V₂, from the stock concentration, the volume of stock used and the final volume.
Moles to Grams Calculator (and Grams to Moles)
Convert moles to grams or grams to moles with the molar mass: mass = moles × molar mass, moles = mass ÷ molar mass.
Theoretical Yield Calculator
Compute the theoretical yield (in grams) of a chemical reaction from the limiting reactant’s mass, the reactant and product molar masses, and the stoichiometric ratio.
Ideal Gas Law Calculator
Solve PV = nRT for pressure, volume, temperature or moles of an ideal gas.
Heat Capacity Calculator
Calculate the heat energy absorbed or released by a substance using its mass, specific heat capacity, and temperature change.
Half-Life Calculator
Find how much of a radioactive substance (or any first-order decay) remains after a given time from its half-life, using N = N₀ × (1/2)^(t / t½).
Percent Composition Calculator
Find the mass percentage of any element in a compound.
Molarity to Molality Converter
Convert solution molarity (mol/L of solution) to molality (mol/kg of solvent) from the solution density and the molar mass of the solute.
Charles's Law Calculator
Determine the final volume of a gas after a temperature change using Charles's Law.
pH Buffer Calculator
Calculate the pH of a weak acid–conjugate base buffer solution using the Henderson-Hasselbalch equation, with a buffer-specific temperature coefficient (dpKa/dT) and a Davies ionic-strength activity correction.
Molarity Calculator
Find the molarity (mol/L) of a solution from the mass of solute, its molar mass and the solution volume, for preparing reagents, buffers and standards.
Osmotic Pressure Calculator
Calculate the osmotic pressure of a solution using the van't Hoff equation.
pH and pOH Calculator
Convert hydrogen ion concentration into pH or pOH, with an activity correction for ionic strength and the temperature dependence of water's ion product Kw.
Buffer Capacity Calculator
Calculate the buffer capacity (β) of a weak acid / conjugate base buffer from the two concentrations, using the Van Slyke equation.
Parts Per Million Calculator
Calculate the concentration of a solute in parts per million (ppm) by mass.