Association Constant (Ka) Calculator

Calculate Ka from dissociation constant, kinetic rates, or equilibrium concentrations

Calculation Method

Select Method

Dissociation Constant (Kd)

Unit

Association Constant (Ka)

1.00 x 10⁸ M^-1

log(Ka)

8.00

Kd

1.000e-8 M

Delta G (at 25C)

-45.66 kJ/mol

Affinity Classification

Moderate affinity (micromolar Kd)

Key Relationships

Ka = 1/Kd = kon/koff
Ka = [RL]/([R][L])
Higher Ka = Stronger binding
deltaG = -RT ln(Ka)