PPM stands for parts per million — a dimensionless ratio representing 1 part of a substance per 1,000,000 parts of the total mixture. It is commonly used to measure concentration in water quality, soil analysis, and air quality testing.

What chemistry tools are available?

CoolConversion offers 23 free chemistry tools: Chemical Equation Balancer, pH Calculator, Molar Mass Calculator, Empirical Formula Calculator, Molarity Calculator, Dilution Calculator (M1V1 = M2V2), Grams to Moles, Moles to Grams, mg to mL, mL to mg, Volume to Mass Converter, Mass to Volume Converter, PPM to mg/L, mg/L to PPM, PPM to PPB, PPB to PPM, PPM to mg/kg, mg/kg to PPM, PPM to µg/L, µg/L to PPM, PPM Conversion Chart, PPM to Percent, and Percent to PPM.

Is PPM a unit of measurement?

Technically, PPM is a dimensionless ratio (mass/mass), not a formal SI unit. However, it is universally used as a practical concentration unit in chemistry, environmental science, and industry. The SI-preferred notation is mg/kg for mass ratios.

What is the difference between mg/L and mg/kg?

mg/L (milligrams per liter) is mass per volume — it depends on solution density. mg/kg (milligrams per kilogram) is mass per mass — it always equals PPM regardless of density. For water (density ≈ 1 kg/L), mg/L and mg/kg are numerically equal.

Which PPM converter should I use?

Use mg/L for water quality testing, mg/kg for soil or food analysis, PPB or µg/L for trace-level contaminants (lead, mercury), and Percent for large concentrations (>10,000 ppm).

Chemistry Calculators & Converters

Chemical Equations & Stoichiometry

Balance chemical equations and work with chemical formulas.

Chemical Equation Balancer
Balance any chemical equation instantly using Gaussian elimination. Supports parentheses, brackets, hydrates, and polyatomic ions. Includes atom-count verification and step-by-step explanation.

Practice Worksheet — 80 Problems (4 difficulty levels)

PPM Concentration Converters

Convert parts per million (PPM) to and from common concentration units used in water quality, soil analysis, and laboratory work.

PPM to mg/L Converter
Convert parts per million to milligrams per liter. For water: 1 ppm = 1 mg/L.
mg/L to PPM Converter
Reverse conversion: milligrams per liter back to parts per million.
PPM to PPB Converter
Convert parts per million to parts per billion. 1 ppm = 1,000 ppb (always).
PPB to PPM Converter
Reverse conversion: parts per billion back to parts per million.
PPM to mg/kg Converter
Convert parts per million to milligrams per kilogram. 1 ppm = 1 mg/kg (always).
mg/kg to PPM Converter
Reverse conversion: milligrams per kilogram back to parts per million.
PPM to µg/L Converter
Convert parts per million to micrograms per liter. For water: 1 ppm = 1,000 µg/L.
µg/L to PPM Converter
Reverse conversion: micrograms per liter back to parts per million.

Solution Calculators

Advanced calculators for laboratory solution preparation.

Molarity Calculator
Calculate molar concentration (M = mol/L) from mass, molecular weight, and volume. Four modes: find molarity, mass, volume, or moles.
Dilution Calculator (M₁V₁ = M₂V₂)
Calculate stock volume, final concentration, or final volume for solution dilutions. Enter any three values to find the fourth.
pH Calculator
Calculate pH of strong acids, strong bases, weak acids, and buffer solutions. Also converts between pH, pOH, [H⁺], and [OH⁻].

Mass, Moles & Molecular Weight

Calculate molar mass of any compound and convert between mass and moles.

Molar Mass Calculator
Calculate molar mass (molecular weight) of any chemical compound. Supports parentheses, brackets, and hydrates. Try NaCl, H₂SO₄, or Ca(OH)₂.
Empirical Formula Calculator
Find the empirical and molecular formula from percent composition, or calculate percent composition from any chemical formula.
Grams to Moles Calculator
Convert mass in grams to moles using molecular weight. Formula: n = m ÷ MW.
Moles to Grams Calculator
Convert moles to mass in grams using molecular weight. Formula: m = n × MW.

Mass ↔ Volume (mg / mL)

Convert between milligrams and milliliters using density (pure substances) or concentration (solutions and medications).

mg to mL Converter
Convert milligrams to milliliters using substance density or solution concentration. For water, 1,000 mg = 1 mL.
mL to mg Converter
Convert milliliters to milligrams for any substance. For water, 1 mL = 1,000 mg.

Convert between volume and mass for nearly 200 common chemical substances using their density — from water and ethanol to sulphuric acid and glycerol.

Volume to Mass Converter
Convert any volume to its equivalent mass for 195 chemical substances. Pick a substance and the calculator applies m = d × v automatically.
Mass to Volume Converter
Inverse calculator: given the mass of a substance, find the corresponding volume using its density.

Reference & Percent Converters

Quick-reference charts and PPM ↔ Percent conversions.

PPM Conversion Chart
Cross-reference table showing PPM equivalents in mg/L, PPB, mg/kg, µg/L, and percent at a glance.
PPM to Percent Calculator
Convert PPM to percentage. Formula: % = PPM ÷ 10,000.
Percent to PPM Calculator
Convert percentage to PPM. Formula: PPM = % × 10,000.

PPM Quick Reference

1 PPM equals:

Equals	Unit	Notes
0.0001%	Percent	Always
1,000 ppb	Parts per billion	Always
1 mg/L	Milligrams per liter	Water only (d ≈ 1 kg/L)
1 mg/kg	Milligrams per kilogram	Always (mass/mass)
1,000 µg/L	Micrograms per liter	Water only (d ≈ 1 kg/L)