Dilution and concentration calculator
Leave exactly one field blank.
C₁V₁ = C₂V₂, plus percentage, molarity and ppm conversions.
How it works
Solves the dilution equation for whichever value is missing, and converts between percentage, molarity, ppm and mg/L.
The dilution equation works because the amount of solute does not change — only the volume it is spread through. Concentration times volume is that amount, so the product is the same on both sides.
One safety point that belongs on any page about this: always add acid to water, never water to acid. Dilution releases heat, and adding water to concentrated acid concentrates that heat in a small volume at the surface, which can boil and spatter acid. Adding acid to a larger volume of water spreads the heat through the bulk.
For dilute aqueous solutions, 1% by mass is about 10,000 ppm and 1 mg/L is about 1 ppm, because a litre of water weighs a kilogram. That approximation breaks down for concentrated solutions and for anything not water-based.
This tool runs entirely in your browser. Nothing you enter is sent to a server, logged or stored, and the page keeps working with the network disconnected.
Common questions
- What is the dilution formula?
- C₁V₁ = C₂V₂. The amount of solute is unchanged, so concentration times volume is equal before and after.
- Do you add acid to water or water to acid?
- Acid to water, always. Dilution is exothermic, and adding water to concentrated acid concentrates that heat at the surface where it can boil and spatter.
- How do percent and ppm relate?
- For dilute aqueous solutions, 1% is roughly 10,000 ppm, since a litre of water weighs a kilogram. The approximation fails for concentrated or non-aqueous solutions.
Related pages
- Percentage calculator Work out a percentage of a number, what percent one number is of another, and percentage change.
- Loan and EMI calculator Monthly payment, total interest and total repaid for any loan amount, rate and term.
- BMI calculator Body mass index from height and weight, in metric or imperial, with what the number does and does not mean.
- Tip calculator Work out a tip and split the bill, with the per-person figure rounded sensibly.
- Age calculator Exact age in years, months and days from a date of birth, plus total days and the next birthday.
- Paint calculator How much paint a room needs, allowing for doors, windows and the number of coats.
- Compound interest calculator Growth of a lump sum plus regular contributions, with the interest shown separately.
- Calorie and BMR calculator Resting metabolic rate and daily calorie needs by activity level.
- Dog age calculator A dog's age in human years, using the research formula rather than multiplying by seven.
- Discount calculator Find the sale price and how much you save, including stacked discounts and tax.
Sources
- Calculated on this page — At One Place