Equilibrium Constant (Kc) Calculator

Calculate Kc from equilibrium concentrations and stoichiometric coefficients.

Calculator

For aA + bB ⇌ cC + dD, enter equilibrium concentrations and coefficients to calculate Kc = [C]^c[D]^d / [A]^a[B]^b.

Kc2.0000e+0

Formula and assumptions

Kc = [products]^coefficients / [reactants]^coefficients

Enter equilibrium concentrations for the species included in the expression. The generic four-term form represents aA + bB ⇌ cC + dD.

Assumption: Entries represent equilibrium concentrations for the species included in the expression.

Variables and units

  • Kc — concentration equilibrium constant
  • [A], [B], [C], [D] — equilibrium concentrations
  • coefficient — balanced-equation stoichiometric coefficient

Worked example

For A + B ⇌ C with [A] = 1, [B] = 1 and [C] = 2, Kc = 2.

Important limits

Activities, solids, pure liquids, temperature dependence and reaction balancing are not evaluated.

Reference and related tools

OpenStax: Equilibrium constants. Return to Chemistry Calculators for the other tools in this group.