Convert Magnesium ppm to Magnesium Meq/100g


What is Magnesium ppm?

  • ppm means “parts per million.”
  • It tells you how many parts of Magnesium are in one million parts of soil.
  • For example, 100 ppm means there are 100 parts of Magnesium in one million parts of soil.

What is Magnesium Meq/100g?

  • Meq/100g means milliequivalents of Magnesium per 100 grams of soil.
  • It measures the amount of charge (chemical activity) of Magnesium in the soil.
  • This unit is useful because it relates to how plants absorb nutrients.

Why convert ppm to Meq/100g?

  • Different soil tests report Magnesium in different units.
  • To compare or use results properly for fertilizing, you may need to convert ppm to Meq/100g.
  • Meq/100g helps understand the nutrient availability to plants better.

How to convert Magnesium ppm to Meq/100g?

  1. Know the atomic weight of Magnesium:
    Magnesium atomic weight = 24.3 g/mol

  2. Know the valence (charge) of Magnesium ion:
    Magnesium ion (Mg²⁺) has a charge = 2

  3. Conversion formula:

    Meq/100g=ppm of Mg/Atomic weight of Mg×Valence

  4. Plug in values:

    Meq/100g=ppm Mg/24.3×2

Example:

If your soil has 48 ppm Magnesium, then:

Meq/100g=48/24.3×2=3.95 Meq/100g

Summary:

Step Value / Formula
Atomic weight of Mg 24.3
Valence (charge) of Mg 2
Formula Meq/100g=ppm24.3×2
Example (48 ppm) 3.95 Meq/100g

You can find more agriculture conversion calculators here.