PPM Calculator
Enter a solute mass and a solution mass to get the concentration in parts per million — plus the equivalent percentage — and see how tiny amounts add up.
PPM and percent at once
Enter the solute mass and the solution mass and the PPM calculator returns the concentration in ppm and the same value as a percentage together.
Match the units
Use the same mass unit for both fields, and make sure the solution mass includes the solute — it is the total mass of the whole mixture.
What is ppm?
Parts per million
Parts per million (ppm) is a way of expressing a very small concentration: how many parts of a solute there are for every million parts of the whole solution. The PPM calculator turns two measurements — the mass of the solute and the total mass of the solution — into a concentration in ppm, alongside the same value written as a percentage. It is the number behind drinking-water limits, air-quality readings, and lab dilutions, where a few parts in a million still matter.
Enter the mass of the solute and the mass of the solution to get the concentration in ppm and as a percentage instantly.
Parts per million is the mass of the solute divided by the mass of the solution, multiplied by one million. The percentage is simply the ppm value divided by 10,000.
ppm = (mass of solute ÷ mass of solution) × 1,000,000Because ppm is a ratio, the units cancel — use the same unit for both masses and the result is the same. One percent equals 10,000 ppm, so dividing the ppm value by 10,000 gives the percentage. For dilute water solutions, 1 ppm is roughly 1 mg per litre.
Suppose 0.005 g of a substance is dissolved in 1000 g of solution.
Divide the masses
0.005 ÷ 1000 = 0.000005 — the fraction of the solution that is solute.
Scale to a million
0.000005 × 1,000,000 = 5 — the concentration in parts per million.
Convert to percent
5 ÷ 10,000 = 0.0005 % — the same concentration as a percentage.
The two outputs describe the same concentration in two scales. The ppm figure (5 ppm above) is the natural unit for trace amounts: a drinking-water guideline might cap a contaminant at a few ppm, and pool chlorine is dosed at single-digit ppm. The percentage (0.0005 %) is the same number rescaled, and it shows just how small a few ppm really is. A handy anchor is that 10,000 ppm equals one percent, so 1 ppm is one ten-thousandth of a percent. For dilute water solutions you can also read ppm as milligrams per litre, since a litre of water weighs about a million milligrams — so 5 ppm is close to 5 mg/L. Pushing the solute mass up or the solution mass down both raise the concentration, but ppm is a ratio, so doubling both masses leaves it unchanged.
The formula is exact, but a couple of practical points are worth keeping in mind.
Mass basis and consistent units
This calculator works on a mass basis (mass of solute over mass of solution), which is the most common definition of ppm. Volume-based or mole-based ppm can differ, so check which one a standard requires. Keep your units consistent — the same mass unit for both fields — and remember the solution mass is the total, including the solute, or the concentration will be wrong.