8 free interactive chemistry calculators with reverse solving. Enter any known values and solve for any unknown.
Calculate the molarity (M) of a solution given moles of solute and volume of solution. Supports reverse solving — leave any one field empty to solve for it.
Calculate molar mass from mass and moles, or find any unknown variable. Leave one field empty to solve for it.
Calculate any variable in the Ideal Gas Law equation. Uses R = 0.08206 L·atm/(mol·K). Leave one field empty to solve for it.
Calculate pH from hydrogen ion concentration, or find [H⁺] from pH. Also calculates pOH and [OH⁻] automatically.
Calculate dilution using the dilution equation. Leave one field empty to solve for it.
Convert between mass, moles, and number of particles using molar mass and Avogadro's number.
Calculate the percent composition of an element in a compound given the element's mass contribution and the compound's molar mass.
Calculate Gibbs free energy change to determine reaction spontaneity. Leave one field empty to solve for it.
Periodic Table Online provides 8 interactive chemistry calculators: Molarity, Molar Mass, Ideal Gas Law, pH, Dilution, Stoichiometry, Percent Composition, and Gibbs Free Energy.
Yes. All calculators support reverse solving — leave any one field empty and the calculator automatically solves for that unknown.
Yes, all 8 chemistry calculators are completely free to use with no account required.
The Ideal Gas Law formula is PV = nRT, where P is pressure (atm), V is volume (L), n is moles, R is the gas constant (0.08206 L·atm/mol·K), and T is temperature (K).