Titration Concentration: How to Calculate It

Updated 11 November 2026 · Standard formula, shown below

This guide explains how to calculate the concentration of an unknown solution from titration data. You will need the known concentration of the titrant, the volumes used, and the balanced chemical equation. The result is the molarity (mol/L) of the analyte, which is essential for acid-base, redox, and other titration analyses.

What You’ll Need

Balanced chemical equation for the titration reaction
Volume of titrant used (from the burette, in mL or L)
Concentration of the titrant (in mol/L or M)
Volume of the analyte (the solution being analyzed, in mL or L)
Stoichiometric coefficients from the balanced equation (e.g., 1:1, 1:2)
Calculator (optional but helpful)

Step-by-Step

Write the balanced chemical equation. For example, for HCl titrated with NaOH: HCl + NaOH → NaCl + H₂O. Note the coefficients in front of each reactant and product.
Record the volume of titrant used. This is the difference between the final and initial burette readings. Convert to liters if needed (divide mL by 1000).
Record the volume of the analyte. This is the volume of the solution you placed in the flask or beaker before titration. Convert to liters as well.
Calculate the moles of titrant used. Use the formula: moles = concentration (mol/L) × volume (L). For example, if you used 0.100 M NaOH and 25.0 mL (0.0250 L), then moles NaOH = 0.100 × 0.0250 = 0.00250 mol.
Use the stoichiometry to find moles of analyte. Look at the balanced equation. If the coefficient of the analyte is ‘a’ and that of the titrant is ‘b’, then moles analyte = (moles titrant) × (a/b). For a 1:1 reaction, they are equal. For example, if the equation is 2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂O, then 1 mole of H₂SO₄ reacts with 2 moles of NaOH, so moles H₂SO₄ = moles NaOH / 2.
Calculate the concentration of the analyte. Divide the moles of analyte by the volume of the analyte (in liters): concentration (mol/L) = moles / volume (L).
Report with correct units and significant figures. Use the same number of significant figures as the least precise measurement. Typically, concentrations are reported in mol/L (M) or sometimes in g/L.

Common Mistakes

Forgetting to convert mL to L. Always convert volumes to liters before using them in calculations, because concentration is in mol/L.
Ignoring stoichiometric coefficients. A 1:2 or 2:1 reaction requires adjusting the mole ratio. Using a 1:1 assumption when it is not true gives a wrong answer.
Using the wrong volume for the analyte. The volume of the analyte is the volume you pipetted into the flask, not the total volume after adding water or indicator.
Misreading the burette. Always read the bottom of the meniscus at eye level, and record to two decimal places (e.g., 25.00 mL).
Rounding too early. Keep extra digits during intermediate steps and round only at the final answer.

Tips

Do a rough titration first. This helps you know the approximate endpoint and avoid overshooting on the precise runs.
Use a white tile under the flask to see the color change clearly.
Rinse the burette with the titrant before filling, and the pipette with the analyte, to avoid dilution.
Remove air bubbles from the burette tip before starting.
Swirl the flask continuously to ensure thorough mixing and a sharp endpoint.
Repeat at least three times and average the results for accuracy, discarding any outliers.

Troubleshooting

Endpoint is not sharp or color fades quickly: This may be due to a stale indicator, incorrect indicator choice, or the presence of CO₂. Use a fresh indicator and ensure the solution is well mixed. For weak acid-strong base titrations, choose an indicator with a pH range matching the equivalence point.
Overshot the endpoint: If you added too much titrant, you cannot simply subtract. Start over with a fresh sample. If you are close, you might be able to back-titrate with a known acid, but it is simpler to redo.
Volume of titrant used is extremely small or large: If less than 10 mL, use a smaller burette or dilute the titrant. If more than 50 mL, use a more concentrated titrant or a larger volume of analyte.
Results vary widely between trials: Check for consistent technique, clean glassware, and accurate volume readings. Ensure you are using the same endpoint color each time.
Calculated concentration seems unreasonable: Double-check the stoichiometric coefficients and unit conversions. Also verify that you used the correct volume of analyte (not the total flask volume).

Frequently Asked Questions

What is the formula for titration concentration?

The core formula is C₁V₁ = C₂V₂ for a 1:1 reaction, where C is concentration and V is volume. For non-1:1 reactions, you must include the mole ratio: C₁V₁ / a = C₂V₂ / b, where a and b are the stoichiometric coefficients.

Do I need to convert mL to L?

Yes, because molarity is moles per liter. If you use mL in the formula without converting, you will get a result that is off by a factor of 1000. Always convert to liters before calculating moles.

What if the reaction is not 1:1?

Use the balanced equation to find the mole ratio. For example, in H₂SO₄ + 2NaOH → Na₂SO₄ + 2H₂O, 1 mole of H₂SO₄ reacts with 2 moles of NaOH. So moles H₂SO₄ = moles NaOH ÷ 2.

How do I find the endpoint in a titration?

The endpoint is detected by a color change of an indicator (e.g., phenolphthalein turns pink in basic solutions). It should be a permanent color change that persists for at least 30 seconds with swirling.

What is the difference between endpoint and equivalence point?

The equivalence point is the exact point where the moles of acid and base are stoichiometrically equal. The endpoint is when the indicator changes color. A good indicator changes color at or very near the equivalence point, but they are not always identical.

Can I use this method for redox titrations?

Yes, the same principle applies. You need the balanced redox equation to determine the mole ratio between the oxidant and reductant. The rest of the calculation is identical.

Method: the standard formula for this calculation, rounded as each result states. See how the calculators work or report an error.