Enter the milligrams (mg) of substance, valence, and molecular weight into the calculator to determine the mEq.

## mEq Formula

The following formula is used to calculate the milliequivalent (mEq) of a substance.

mEq = mg * V / MW

- where mEq is the milliequivalent
- mg is the milligrams of substance
- V is the valence of the substance
- MW is the molecular weight of the substance

To calculate mEq, multiply the milligrams by the valence of the substance, then divide by the molecular weight of the substance.

## mEq Definition

mEq is short for milliequivalent. The milliequivalent is a measure of the combining power of an element relative to the activity of 1 mg of hydrogen. This term is most often associated with electrolytes.

## Example Problem

How to calculate mEq?

**First, determine the mg of the substance.**In this example, there is a total of 25mg of substance.

**Next, determine the valence.**The valence of this material is 3.

**Next, determine the molecular weight.**The molecular weight is found to be 40 mg/mol.

**Finally, calculate the mEq.**Using the formula above, the milliequivalent is calculated to be:

mEq = mg * V / MW

mEq = 25*3/40

mEq = 1.875