Alligation Calculator

Enter your high concentration solution, low concentration solution, and desired concentration with its total volume, and the Alligation Calculator works out the exact mixing ratio — plus the precise volume of each solution and their respective parts — so you blend the right amounts every time.

%
%
%
mL

Results

Mixing Ratio

--

Volume of High Concentration

--

Volume of Low Concentration

--

Parts of High Concentration

--

Parts of Low Concentration

--

Solution Volume Breakdown

Frequently Asked Questions

What is the alligation method?

Alligation is a mathematical method used to calculate the proportions in which two solutions of different concentrations must be mixed to produce a solution of a desired intermediate concentration. It's commonly used in pharmacy and chemistry.

How do you calculate alligation ratios?

The alligation ratio is calculated using the cross-difference method: Parts of high concentration = |Low concentration - Desired concentration|, and Parts of low concentration = |High concentration - Desired concentration|. The ratio is then parts of high : parts of low.

Is alligation the same as dilution?

No, alligation and dilution are different. Dilution involves adding a solvent to reduce concentration, while alligation involves mixing two solutions of different concentrations to achieve a target concentration between them.

Can I use alligation for any type of solution?

Yes, alligation can be used for any homogeneous solutions as long as the components are miscible and the concentrations are expressed in the same units (%, molarity, ppm, etc.).

What if my desired concentration is outside the range of my two solutions?

The desired concentration must be between the high and low concentrations for alligation to work. If it's outside this range, you cannot achieve it by mixing these two solutions.

How accurate are alligation calculations?

Alligation calculations are mathematically precise, but practical accuracy depends on measurement precision and assumes ideal mixing behavior. Always verify results experimentally for critical applications.

What are common applications of alligation in pharmacy?

In pharmacy, alligation is used to prepare solutions of specific concentrations, mix ointments or creams with different active ingredient percentages, and prepare IV solutions with precise drug concentrations.

More Chemistry Tools