Buffer Capacity Calculator

Calculate buffer capacity and design optimal pH buffer solutions

Common Buffer Systems

Buffer Fundamentals

Buffer Capacity (β): Amount of acid/base that can be added per unit pH change

Optimal Range: pH = pKa ± 1 for maximum effectiveness

Maximum β: Occurs when pH = pKa (equal concentrations of acid and base)

Henderson-Hasselbalch: pH = pKa + log([A⁻]/[HA])

Understanding Buffer Capacity

Buffer capacity (β) quantifies a buffer solution's ability to resist pH changes when acids or bases are added. It represents the amount of strong acid or base (in moles) that must be added to 1 liter of buffer to change the pH by 1 unit. Buffers are most effective when pH equals pKa and within the range pKa ± 1.