pKa & pH Calculator

Calculate buffer parameters using Henderson-Hasselbalch equation

Buffer Analysis

pH = pKa + log([A⁻]/[HA])

What do you want to calculate?

pH← Calculating

pKa

Ratio [A⁻]/[HA]

Common Ratios:

Acetic Acid4.76

pH range: 3.8-5.8

Phosphate (pKa2)7.20

pH range: 6.2-8.2

HEPES7.55

pH range: 6.8-8.2

Tris8.06

pH range: 7.0-9.0

Borate9.24

pH range: 8.2-10.2

pH = pKa[A⁻] = [HA]

pH = pKa - 1[A⁻]/[HA] = 0.1

pH = pKa + 1[A⁻]/[HA] = 10