Work out the concentration of an unknown solution from your titration results. Enter the titrant concentration, titre volume, sample volume and the mole ratio from the balanced equation, and this free titration calculator gives the answer with the working, for acid-base and redox titrations.
Titration formula
Worked example
25.0 mL of NaOH is titrated with 0.100 M HCl, and the average titre is 24.6 mL. HCl + NaOH → NaCl + H₂O, so the ratio is 1:1. Moles HCl = 0.100 × 0.0246 = 0.00246 mol = moles NaOH, so C(NaOH) = 0.00246 ÷ 0.0250 = 0.0984 M.
For H₂SO₄ + 2NaOH, set a = 1 (acid) and b = 2 (base) if the acid is in the burette. For the permanganate–iron(II) redox titration MnO₄⁻ + 5Fe²⁺, use a = 1 and b = 5.
Tips for accurate titrations
- Repeat until you have two or three concordant titres (within 0.10 mL) and average them.
- Read the burette at eye level from the bottom of the meniscus.
- Choose an indicator that changes colour at the equivalence point: phenolphthalein for strong base titrations, methyl orange for strong acid–weak base.
Frequently asked questions
How do I calculate concentration from a titration?
Find moles of titrant (C × V in litres), use the mole ratio from the balanced equation to get moles of the sample, then divide by the sample volume. Leave C_B empty and the calculator does all three steps.
What mole ratio should I enter?
The coefficients of the titrant (a) and sample (b) in the balanced equation. For HCl + NaOH both are 1; for H₂SO₄ + 2NaOH, the acid is 1 and the base is 2.
Can I use mL for volumes?
Yes. Choose mL in the unit menu; the calculator converts to litres for you.
Does it work for redox titrations?
Yes, any titration with a known balanced equation, including permanganate, dichromate and iodine/thiosulfate titrations.
Related tools
Free educational tool by HawkInc. Results are calculated in your browser and rounded for display; check critical work by hand or with a second method.