Solution Concentration Calculator

How to use the Solution Concentration Calculator

1. 1Enter grams of solute, solution volume and optionally the molar mass.
2. 2Pick the units or options from the menus if the solution concentration tool offers them.
3. 3Read the solution concentration in the large result box.
4. 4Look at the extra rows for related figures.
5. 5Press Copy result to keep the answer.

When you need the solution concentration

Students, lab technicians, aquarists and gardeners use it to prepare and check solutions.

Use the volume of the final solution, not the volume of solvent you started with. For dilute water solutions, ppm is roughly the same as mg per litre.

How the solution concentration is worked out

g/L = grams ÷ litres. % w/v = grams ÷ mL × 100. ppm (mg/L) = g/L × 1,000. Molarity = (grams ÷ molar mass) ÷ litres. 5.85 g of table salt in 100 mL of solution is 58.5 g/L, 5.85% w/v, 58,500 ppm and, with a molar mass of 58.44 g/mol, a molarity of 1.00 M.

Every answer on this page comes from that one rule, so you can check any result by hand with a calculator. The figures shown underneath, such as other units, are conversions of the same answer.

• Four concentration units
• Optional molarity
• Handles small and large amounts

Mistakes to avoid with solution concentration

Do not mix up grams per litre with percent: 10 g in 100 mL is 10% w/v, which is 100 g/L. Molarity needs the correct molar mass for the exact substance.

On phone and computer

On a phone, type into the boxes one after another and read the solution concentration underneath; Copy result puts it on the clipboard for a message or a note. On a computer the inputs sit on the left and the answer on the right, so you can change one figure and watch the solution concentration move. The solution concentration calculator works the same on both.

Checking your solution concentration by hand

A good habit is to test the solution concentration calculator with a case you already know. 5.85 g of table salt in 100 mL of solution is 58.5 g/L, 5.85% w/v, 58,500 ppm and, with a molar mass of 58.44 g/mol, a molarity of 1.00 M.

If your own figures give a surprising answer, repeat the working yourself: g/L = grams ÷ litres. % w/v = grams ÷ mL × 100. ppm (mg/L) = g/L × 1,000. Molarity = (grams ÷ molar mass) ÷ litres. Small differences usually come from rounding, from mixing units, or from a typing slip in one of the inputs. Concentration can be written several ways, so check the unit. Use the Dilution Calculator to weaken a solution, the Molarity Calculator for moles per litre, and the Percentage Calculator for simple percentages.

Features

• Use final volume
• w/v is not w/w
• Check the molar mass
• Clear messages when the solution concentration inputs make no sense
• Copy the result with one tap
• Private: nothing is uploaded

Frequently asked questions