Binding Affinity Calculator

Calculate binding affinity parameters including Kd, Ka, and Gibbs free energy of binding

Binding Parameters

Dissociation Constant (Kd)

Unit

Temperature (K)

Standard: 298.15 K (25C)

Ligand Concentration (nM)

Receptor Concentration (nM)

Association Constant (Ka)

1.000e+8 M^-1

Delta G

-45.66 kJ/mol

Fraction Bound

90.10%

Kd in Molar

1.000e-8 M

Affinity Classification

High affinity (nanomolar)

Key Relationships

Ka = 1/Kd
deltaG = RT ln(Kd)
Lower Kd = Higher affinity
More negative deltaG = Stronger binding