PPM/PPB Concentration Calculator

PPM, PPB, percentage, and per mille are all ways to express how concentrated one substance is within another — and the PPM/PPB Concentration Calculator converts between all four in one place. Enter a value into any concentration field (ppm, ppb, %, or ‰) to see it instantly expressed in all other units. For dilution work, enter your stock concentration, stock unit, stock volume (V1), final concentration, final unit, and final volume (V2) to calculate the dilution factor needed to reach your target solution.

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Results

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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Frequently Asked Questions

What's the difference between ppm and ppb?

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.

How do I convert ppm to percent?

To convert ppm to percent, divide by 10,000. The formula is: percent = ppm ÷ 10,000. For example, 5,000 ppm equals 0.5%.

Is ppm the same as mg/L?

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.

How many ppm is 1 percent?

1 percent equals 10,000 ppm. This is because percent means parts per hundred, and there are 10,000 hundreds in one million.

When should I use ppb instead of ppm?

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.

What's a safe chlorine level in drinking water?

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.

How do I use the dilution calculator?

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.

What does per mille (‰) mean?

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.