Chemistry
Buffer Capacity Calculator
Measure how much strong acid or base a buffer absorbs for each unit of pH change.
Your inputs
Change any value to update the result instantly.
Buffer capacity (β)
0.05 mol/(L·pH)
Acid or base added per litre
0.01 mol/L
pH shift
0.2 pH units
Direction
Acid was added — the pH fell
Reading
A weak buffer — the pH moved easily
This is the operational capacity over the pH range you measured, not the differential capacity dβ/dpH.
What this calculator does
Measures how many moles of strong acid or base one litre of buffer absorbs per unit of pH change.
What your result means
A larger beta means the buffer resists pH change better over the range you measured.
Formula and working
β = (n_added ÷ V) ÷ |ΔpH|
- 1
Collect the inputs
Strong acid or base added (n) = 0.01 mol; Buffer volume (V) = 1 L; pH before addition = 4.75; pH after addition = 4.55
- 2
Apply the formula
β = (n_added ÷ V) ÷ |ΔpH|
- 3
Result
Buffer capacity (β) = 0.05 mol/(L·pH)
Frequently asked questions
Symbols and assumptions
- beta
- Buffer capacity in mol per litre per pH unit
- n
- Moles of strong acid or base added
- V
- Buffer volume in litres
- • The acid or base added is strong and fully dissociated.
- • Volume change on addition is negligible.
Sources and review
Reviewed 2026-09-22 · Next review 2027-09-22
- • This is the operational capacity across a finite pH step, not the differential capacity d(beta)/d(pH) at a single point.
Important limitation
This is an educational estimate based only on the values and formula shown. Verify current rates, rules, units, and professional standards before relying on the result. It is not personalized financial or investment advice.
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