🧪 Concentration Dilution Calculator
Calculate the final concentration when diluting a solution.
Solution A (Original)
Target Concentration after Dilution
What is Dilution?
Dilution means adding water (solvent) to lower the concentration. The amount of solute (salt) does not change.
Dilution Formula
Salt of A = Amount of A × Concentration of A / 100
Water needed = (Salt of A / Target × 100) − Amount of A
Final Amount = Amount of A + Water added
Worked examples
200 g of a 20% solution holds 40 g of solute; to reach 10% the total must be 400 g, so 200 g of water is added.
Doubling the mass halves the percentage: 50 g of a 30% solution diluted to 100 g becomes 15%.
What the dilution assumes
The solute mass stays constant and the added water carries none of it. Percentages are mass fractions, so volumes need a density conversion first. Mixing volumes is not strictly additive, temperature changes density, and diluting a strong acid releases significant heat — add acid to water, never the reverse.
Frequently asked questions
- How much water halves the concentration?
- An amount equal to the current solution mass. 200 g of 20% becomes 400 g of 10% by adding exactly 200 g of water.
- Does C₁V₁ = C₂V₂ apply here?
- It is the volume version of the same conservation law. With mass percentages the equivalent is m₁ × c₁ = m₂ × c₂, which is what this calculator solves.
- Why does the tool ask for grams?
- Because mass percentages are defined per 100 g, which makes the arithmetic exact and independent of density and temperature.