Buffer Solution pH Calculator
Buffer pH from the Henderson-Hasselbalch equation.
Enter your values
ⓘ Live results
Results
- Buffer pH
- 4.76
- Ratio [base]/[acid]
- 1
- pKa used
- 4.76
Quick answer
pH = pKa + log10([base]/[acid]).
pH = pKa + log10([A-]/[HA])
How to use the Buffer Solution pH Calculator
- 1Enter the pKa of the weak acid (4.76 for acetic acid is a common example).
- 2Enter the concentrations of the conjugate base and the weak acid.
- 3Read the resulting buffer pH.
Worked example
Using the values the calculator loads with:
Inputs
- Acid pKa4.76
- Conjugate base concentration0.1 M
- Weak acid concentration0.1 M
Results
- Buffer pH4.76
- Ratio [base]/[acid]1
- pKa used4.76
Frequently asked questions
What makes a good buffer?
A buffer works best within 1 pH unit of the acid's pKa, where the base-to-acid ratio stays balanced.
What if the ratio is 1:1?
When base and acid concentrations are equal, pH equals pKa exactly since log10(1) = 0.
About this calculator
- Built and reviewed by James Whitfield · How we build and test calculators
- Report an error
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.