PPM to mg/L Calculator
Convert mass-based ppm to mg/L using the solution density you supply.
Formula
mg/L = ppm (mg/kg) × ρ (kg/L)
Solution density: 1,000 kg/m³ · Mass concentration ≈ (100)×(1,000 kg/m³)÷1000
How to use
- Enter ppm defined by mass, equivalent to mg/kg.
- Enter the density of the entire solution.
- Read the mass concentration in mg/L.
Examples
- 250 ppm at 0.8 kg/L gives 200 mg/L.
Frequently asked questions
Is 1 ppm always 1 mg/L?
Only at a solution density of 1 kg/L. For dilute water this is an approximation.
Can I use gas ppm by volume?
No. Volume-based or mole-based ppm needs a different model.
Which density should I enter?
Use the solution density at its actual temperature, not the pure solute density.
Sources
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