Convert between parts per million (ppm), parts per billion (ppb), and percentage concentrations instantly with accurate calculations and real-world reference values.
Parts per Million
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Parts per Billion
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Percentage
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Per Mille
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Dilution Factor
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PPM (parts per million) means 1 part in 1,000,000 parts total, while PPB (parts per billion) means 1 part in 1,000,000,000 parts total. PPB is 1,000 times smaller than ppm, making it useful for measuring very low concentrations.
To convert ppm to percent, divide by 10,000. The formula is: percent = ppm ÷ 10,000. For example, 5,000 ppm equals 0.5%.
For dilute aqueous solutions, ppm is approximately equal to mg/L because water has a density of about 1 g/mL. However, this equivalence only holds for water-based solutions at standard conditions.
1 percent equals 10,000 ppm. This is because percent means parts per hundred, and there are 10,000 hundreds in one million.
Use ppb for very low concentrations, typically when dealing with trace contaminants, environmental monitoring, or when ppm values would result in small decimal numbers. PPB provides better precision for these measurements.
The EPA allows up to 4 ppm of chlorine in drinking water. Most municipal water contains 0.2-2.0 ppm. Above 4 ppm, water may have a strong taste and odor.
Enter your stock concentration, the volume you want to remove, and your desired final concentration and volume. The calculator uses the formula C1×V1 = C2×V2 to determine the dilution factor needed.
Per mille means parts per thousand, similar to how percent means parts per hundred. It's commonly used in oceanography for salinity measurements and in finance for small percentage changes.