Titration Calculator
Find an unknown concentration from a titration.
From the balanced equation
Results update as you type.
How it works
Titration is a laboratory technique for finding the concentration of an unknown solution by reacting it with a solution of known concentration, and this calculator computes the result. You enter the known solution's concentration and volume, the volume of the unknown solution used, and the mole ratio between the two reactants from the balanced chemical equation, and it returns the unknown concentration. The principle is that at the equivalence point, the reactants have combined in exactly the proportions given by the balanced equation. The calculator multiplies the known concentration by its volume to get its moles, scales by the mole ratio to find the moles of the unknown, and divides by the unknown's volume to get its concentration. For a simple one-to-one reaction, such as a strong acid neutralizing a strong base in equal proportions, the mole ratio is one, and the formula reduces to the familiar relationship that concentration times volume of one equals concentration times volume of the other. When the balanced equation is not one-to-one, for example an acid with two acidic protons reacting with a base, you must enter the correct ratio. Volumes can be in any unit, commonly milliliters, as long as both use the same unit. Chemistry students and analysts use titration to determine acid, base, and other concentrations. Enter the known values and mole ratio to compute the unknown concentration.
C_unknown = (C_known × V_known × ratio) / V_unknown
In a titration, the moles of the known solution equal the moles of the unknown, adjusted by the mole ratio from the balanced equation. The unknown concentration equals the known concentration times its volume times the mole ratio of unknown to known, divided by the unknown's volume. Volumes can be in any matching unit since they appear as a ratio.
Source:Analytical chemistry
We review all our tools from time to time to ensure accuracy.
Worked example
How to use this calculator
- 1
Enter your values
Enter known concentration, known volume and unknown volume.
- 2
Adjust the options
Adjust mole ratio (unknown : known) if they apply — sensible defaults are already set.
- 3
Read your result
Unknown concentration updates instantly as you type — no button to press.
Frequently asked questions
What is a titration?
A titration is a technique for determining the concentration of an unknown solution by gradually adding a solution of known concentration until the reaction reaches its equivalence point. By measuring the volumes used and knowing the reaction's stoichiometry, you calculate the unknown concentration. It is widely used in analytical chemistry, especially for acids and bases.
How do you calculate concentration from a titration?
Multiply the known concentration by its volume and by the mole ratio of unknown to known reactant, then divide by the volume of the unknown. This gives the unknown concentration. The calculator applies this formula once you enter the known concentration and volume, the unknown volume, and the mole ratio from the balanced equation.
What is the mole ratio and where do I find it?
The mole ratio is the proportion in which the two reactants combine, taken from the balanced chemical equation. For a one-to-one reaction it is 1. If, for example, two moles of base react with one mole of a diprotic acid, the ratio of acid to base is one to two. Enter the ratio of unknown to known.
What is the equivalence point?
The equivalence point is the moment in a titration when the added known solution has exactly reacted with all of the unknown, in the proportions of the balanced equation. It is often detected with an indicator that changes color or with a pH meter. The volumes at this point are what you use in the calculation.
Do the volume units matter?
The two volumes must be in the same unit, but which unit does not matter because they appear as a ratio that cancels. Milliliters are most common in titrations. As long as you use, say, milliliters for both the known and unknown volumes, the resulting concentration comes out correctly in the same molarity units as your known concentration.