🧫 Henderson-Hasselbalch Equation Calculator

What is the Henderson-Hasselbalch equation?

The Henderson-Hasselbalch equation estimates the pH of a buffer solution made from a weak acid and its conjugate base. It is written as pH = pKa + log10([A⁻]/[HA]), where [A⁻] is the concentration of the conjugate base and [HA] is the concentration of the remaining weak acid.

How this calculator works

Enter the pKa of the weak acid along with the concentrations of the conjugate base and the acid form. The calculator computes the ratio [A⁻]/[HA] and plugs it into the equation to estimate the buffer’s pH.

• When [A⁻] equals [HA], the ratio is 1 and pH equals pKa exactly.
• Buffers work best when the ratio is between roughly 0.1 and 10.

Note: This is a general chemistry education and planning tool, not a substitute for laboratory measurement or professional analytical work.