mg/L to PPM Converter
Convert milligrams per liter (mg/L) to parts per million (ppm). For dilute aqueous solutions, 1 mg/L โ 1 ppm.
PARTS PER MILLION
500 ppm
IN %
0.05%
IN PPB
500,000
NOTE
1 mg/L โ 1 ppm (water)
๐ก How to Convert mg/L to PPM
What Is the Relationship Between mg/L and PPM?
For dilute aqueous solutions (solutions based on water at standard conditions), milligrams per liter and parts per million are essentially interchangeable:
This equality holds because 1 liter of water has a mass of approximately 1,000,000 mg (1 kg = 1,000,000 mg). Therefore, 1 mg dissolved in 1 L of water equals 1 part per 1,000,000 parts = 1 ppm.
When This Approximation Breaks Down
The 1:1 relationship is only accurate when the solution density is close to 1 g/mL (the density of pure water). For concentrated solutions, non-aqueous solvents, or solutions at high temperatures, you need a density correction. You can also use our PPM to mg/L converter for the reverse conversion, or our PPM calculator for general calculations.