Titration Calculator
Enter your titrant molarity, the volume used at the endpoint, and your analyte volume to find the analyte's concentration, plus an illustrative pH curve.
⚗️ What is Titration?
Titration is a laboratory technique for determining the unknown concentration of a solution (the analyte) by slowly adding a solution of precisely known concentration (the titrant) until the reaction between them is complete, a moment called the equivalence point. This calculator takes the titrant's molarity, the volume of titrant used to reach the endpoint, the analyte's original volume, and the reaction's stoichiometric mole ratio, and returns the analyte's concentration.
Titration is a core technique across chemistry: acid-base titrations standardize solutions and determine unknown acid or base concentrations, redox titrations measure things like the vitamin C content of juice or the iron content of an ore sample, and complexometric (EDTA) titrations determine water hardness or metal ion concentrations. Any time a chemist needs to know "how much of X is really in this solution," titration is often the most direct, low-cost answer.
A common point of confusion is treating the endpoint and the true equivalence point as identical. They are closely related but not the same: the equivalence point is the theoretical volume where the stoichiometry is exactly satisfied, while the endpoint is the observed volume where an indicator visibly changes color or an instrument detects a sharp signal change. A well-chosen indicator keeps the two very close together, but a poorly chosen one can introduce a small systematic error.
This calculator also draws an illustrative pH titration curve, the classic S-shaped curve every chemistry student encounters, so you can visualize how pH shifts slowly at first, jumps sharply near the equivalence point, then levels off again, using your entered volumes and concentrations under a simple strong acid-strong base assumption.
📐 Formula
📖 How to Use This Calculator
Steps
💡 Example Calculations
Example 1 — Standard NaOH vs unknown HCl (1:1)
25 mL of unknown HCl is titrated with 0.1 M NaOH, requiring 22.5 mL to reach the endpoint.
Example 2 — Diprotic H2SO4 vs NaOH (2:1)
20 mL of unknown H2SO4 is titrated with 0.15 M NaOH, requiring 28.4 mL to reach the endpoint (2 mol NaOH per mol H2SO4).
Example 3 — HCl vs unknown NaOH (1:1)
15 mL of unknown NaOH is titrated with 0.2 M HCl, requiring 18.75 mL to reach the endpoint.
❓ Frequently Asked Questions
🔗 Related Calculators
What is a titration calculator used for?
A titration calculator finds the concentration of an unknown solution (the analyte) using the known concentration and volume of a titrant added until the reaction reaches its equivalence point (the endpoint). It applies the relationship moles of titrant equals moles of analyte times the stoichiometric mole ratio.
What is the titration formula?
M(analyte) = (M(titrant) x V(titrant)) / (ratio x V(analyte)), where ratio is the number of moles of titrant that react with one mole of analyte. For a simple 1:1 acid-base reaction, ratio = 1, and the formula reduces to the familiar M1V1 = M2V2.
What is the difference between the endpoint and the equivalence point?
The equivalence point is the exact volume of titrant at which moles of titrant equal the stoichiometrically required moles to fully react with the analyte, a theoretical value. The endpoint is the volume at which the indicator visibly changes color or the pH meter reading jumps, the observed value used in practice. A well-chosen indicator makes the endpoint volume very close to the true equivalence point volume.
What mole ratio should I use for a diprotic acid like H2SO4?
Use ratio = 2 when titrating H2SO4 (a diprotic acid) with a monobasic base like NaOH, since it takes 2 moles of NaOH to fully neutralize 1 mole of H2SO4. Conversely, if a dibasic base is the analyte being titrated by a monoprotic acid, the ratio would also be 2, always base the ratio on how many moles of titrant react with one mole of analyte in the balanced equation.
Why does the titration curve show pH 7 at the equivalence point?
The curve on this page specifically illustrates a strong acid titrated by a strong base (or the reverse), a case where the salt formed at the equivalence point does not hydrolyze, so the solution is neutral at pH 7. A weak acid-strong base titration would instead reach the equivalence point at a pH above 7, and a strong acid-weak base titration below 7, this calculator's curve does not model those cases.
Can this calculator be used for redox titrations?
Yes, for the concentration calculation itself, as long as you know the correct stoichiometric mole ratio between the titrant and analyte from the balanced redox half-reactions (for example, ratio = 5 for a permanganate versus oxalate titration). The illustrative pH curve, however, only applies to acid-base titrations and should be ignored for redox titration results.
How do I calculate the concentration of an unknown acid from a titration?
Multiply the titrant's known molarity by the volume used to reach the endpoint to get moles of titrant. Divide by the stoichiometric mole ratio to get moles of analyte. Divide moles of analyte by the analyte's original volume to get its molarity. This calculator performs all three steps automatically from your three inputs.
Why is my titration endpoint volume important to record precisely?
The endpoint volume enters the concentration formula directly as a multiplier, so a small reading error scales proportionally into the final answer. A 1% error in reading a 25 mL burette (about 0.25 mL) produces roughly a 1% error in the calculated analyte concentration, which is why analytical titrations are read to the nearest 0.05 mL or better.
What is a good indicator to choose for a strong acid-strong base titration?
Because the pH jumps sharply through a wide range near pH 7 at the equivalence point of a strong acid-strong base titration, almost any common indicator works well, phenolphthalein (colorless to pink around pH 8.2 to 10) and bromothymol blue (yellow to blue around pH 6 to 7.6) are both commonly used.
Does the titrant have to be a base and the analyte an acid?
No, this calculator works identically regardless of which reagent is the acid and which is the base, or even for non-acid-base reactions like redox or precipitation titrations, as long as you supply the correct molarity, volume, and stoichiometric mole ratio. The illustrative pH curve specifically assumes an acidic analyte being titrated by a basic titrant, since that is the most common classroom case.