Solubility Product (Ksp) Calculator

About this calculator

The solubility product constant (Ksp) describes the equilibrium between a sparingly soluble ionic salt and its dissolved ions: for a salt MₐXᵦ that dissociates as MₐXᵦ ⇌ aMᵇ⁺ + bXᵃ⁻, Ksp = [M]ᵃ[X]ᵇ at saturation, where the ion concentrations are expressed in terms of the molar solubility s using the stoichiometric coefficients (e.g., [M] = as, [X] = bs).

This calculator takes the salt's molar solubility and its ion coefficients and computes Ksp directly, which is the reverse of the more common textbook problem of finding solubility from a known Ksp. Chemistry students and analytical/environmental chemists use it to characterize precipitation reactions, predict whether a salt will dissolve or precipitate under given ion concentrations, and interpret solubility data for applications like water hardness, mineral scaling, and qualitative-analysis lab work.