Use this chemistry calculator to reproduce a named relationship with explicit quantities and units for study, laboratory planning, or an independent numerical check.

Conjugate acid Ka

Required number input.

Compute the Kb of a conjugate base from the Ka of its conjugate acid as Kw divided by Ka. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Conjugate base Kb

The resulting conjugate base kb returned as a number.

• Concentration-based acid–base formulas usually approximate activities and may assume a fixed water ion product. Ionic strength, temperature, polyprotic equilibria, dilution volume, and activity coefficients can materially shift pH and speciation.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Check units and significant figures, compare the result with limiting cases, and use measured or source-specific constants where available. Laboratory, safety, and regulatory decisions require validated methods and appropriate uncertainty analysis.

• Conjugate Acid Ka

  Compute the Ka of a conjugate acid from the Kb of its conjugate base as Kw divided by Kb.

• Ka From Kb

  Compute the acid dissociation constant from the base dissociation constant as Kw divided by Kb.

• Kb From Ka

  Compute the base dissociation constant from the acid dissociation constant as Kw divided by Ka.