How many mEq is 600 mg of potassium? A comprehensive conversion guide

November 23, 2025 •

3 min read

A milliequivalent (mEq) represents the chemical activity of an electrolyte like potassium. For a precise calculation of how many mEq is 600 mg of potassium, the specific compound must be known, as the result varies significantly depending on the source. This guide clarifies the conversion process and explains why this distinction is vital for health.

Quick Summary

The mEq of 600 mg of potassium depends entirely on its chemical form, such as potassium chloride or gluconate, due to differing molecular weights. Accurate conversion requires identifying the compound.

Key Points

Compound Matters: The mEq of 600 mg of potassium depends on the specific chemical compound, such as potassium chloride or gluconate, not just the word 'potassium'.
Potassium Chloride: 600 mg of potassium chloride (KCl) provides approximately 8 mEq of potassium.
Elemental Potassium: 600 mg of pure, elemental potassium is roughly 15.35 mEq, but supplements are almost never in this form.
Conversion Formula: To convert milligrams to milliequivalents, use the formula $mEq = (mg \times valence) / molecular \ weight$.
Clinical Significance: Milliequivalents measure chemical activity, providing a more accurate and standardized dosage measure for electrolytes in a clinical setting.
Read Labels Carefully: Always check the supplement facts for the specific potassium compound to ensure you are calculating the mEq correctly.

The Core of the Calculation: Elemental vs. Salt

Converting milligrams (mg) to milliequivalents (mEq) for potassium requires understanding the difference between elemental potassium and a potassium salt. A dose of 600 mg of elemental potassium will have a different mEq value than the same amount of a compound like potassium chloride or potassium gluconate, where potassium is only part of the total weight. Milliequivalents measure the combining power of a substance based on its valence and molecular weight, making the conversion dependent on the specific compound.

The Formula for Conversion

The general formula to convert milligrams (mg) to milliequivalents (mEq) is:

$mEq = (mg \times valence) / (molecular \ weight \ in \ g/mol)$

For elements like potassium with a valence of +1, the formula simplifies, but still requires the molecular weight. For compounds like potassium chloride (KCl), the molecular weight of the entire compound is used, along with the valence of the potassium ion (K+).

Atomic Weights and Valences

Accurate calculations require specific atomic weights and valences:

Potassium (K): Atomic Weight = ~39.1 g/mol, Valence = 1
Chlorine (Cl): Atomic Weight = ~35.5 g/mol, Valence = 1
Potassium Chloride (KCl): Molecular Weight = ~74.6 g/mol
Potassium Gluconate: Molecular Weight = ~234.3 g/mol

Calculating mEq for Elemental Potassium

If a supplement contains 600 mg of elemental potassium, the calculation is:

$mEq = (600 \ mg \times 1) / 39.098 \ g/mol \approx 15.35 \ mEq$

However, supplements rarely contain only elemental potassium; it's usually in salt form.

Case Study: 600 mg of Potassium Chloride (KCl)

Potassium chloride is a common supplement. 600 mg refers to the weight of the KCl compound. The mEq calculation uses the compound's molecular weight:

$mEq = (600 \ mg \ KCl \times 1) / 74.548 \ g/mol \approx 8.05 \ mEq$

This is consistent with products like K-Tab, which provide 8 mEq of potassium from 600 mg of potassium chloride.

Another Common Form: Potassium Gluconate

Potassium gluconate has a higher molecular weight than KCl. 600 mg of potassium gluconate contains less elemental potassium and thus a different mEq. The elemental potassium content is about 16.7% of the total weight. So, 600 mg of potassium gluconate contains approximately 100 mg of elemental potassium ($600 \times 0.167$). Converting this to mEq: $100.2 \ mg / 39.1 \ g/mol \approx 2.56 \ mEq$. This significant difference underscores the importance of identifying the specific compound.

Why This Difference Matters for Health

Healthcare professionals use milliequivalents because it standardizes the amount of chemically active substance, ensuring consistent physiological effects regardless of the potassium salt. For patients, understanding the difference is crucial for accurate dosing and avoiding potential health issues, especially with conditions like kidney disease or certain medications.

Comparison of Potassium Forms


Compound	Total Weight	Elemental Potassium (mg)	Elemental Potassium (mEq)
Elemental K	600 mg	600 mg	~15.35 mEq
Potassium Chloride	600 mg	~315 mg	~8.05 mEq
Potassium Gluconate	600 mg	~100 mg	~2.56 mEq

Steps for Accurate Conversion

To convert a dosage accurately:

Identify the exact compound. Look for the full name on the label (e.g., "Potassium Chloride").
Find the molecular weight. Use reliable sources for the compound's molecular weight.
Determine the valence. For potassium (K+), the valence is typically 1.
Apply the formula. Use $mEq = (mg \times valence) / molecular \ weight$.
Consult a healthcare provider. Always confirm dosages with a doctor or pharmacist to avoid errors.

Conclusion

The mEq value of 600 mg of potassium is not a single number; it depends on whether it's elemental potassium or a salt like potassium chloride or gluconate. While 600 mg of elemental potassium is about 15.35 mEq, the same amount of potassium chloride is approximately 8 mEq, and potassium gluconate is only about 2.56 mEq. Using milliequivalents is vital for accurate and safe dosing of electrolytes because it measures the substance's chemical activity, which is more relevant clinically than weight alone. Resources like the DailyMed NLM Drug Label for K-Tab provide examples of these conversions for specific products.

Frequently Asked Questions

Using the atomic weight of potassium (approx. 39.1 g/mol), 600 mg of elemental potassium is approximately 15.35 mEq ($600 \div 39.1 \approx 15.35$). This is the value for pure potassium, not a compound.

According to FDA information for products like K-Tab, 600 mg of potassium chloride (KCl) is equivalent to 8 mEq of potassium. The molecular weight of the entire KCl compound is used for this calculation.

Milliequivalents (mEq) are used clinically because they standardize the measurement of an electrolyte's chemical activity or combining power. This is a more relevant measure for physiological function than a simple weight measurement (mg).

First, identify the specific potassium salt (e.g., potassium chloride). Find its molecular weight. Then, use the formula: $mEq = (mg \times valence) / molecular \ weight$. Potassium has a valence of 1.

No. Because potassium gluconate has a higher molecular weight, 600 mg of this compound contains far less elemental potassium. 600 mg of potassium gluconate provides only about 2.56 mEq, compared to 8 mEq from 600 mg of potassium chloride.

Whether a daily intake of 600 mg of potassium is safe depends on the individual's health status, especially kidney function, and the specific potassium compound. Always consult a healthcare provider before starting any new supplement, particularly for electrolyte balance.

The atomic weight of potassium (K) is approximately 39.098 g/mol and can be found on a periodic table or from authoritative chemical databases like PubChem.

Valence is a measure of the combining power of an element. For electrolytes like potassium (K+), it refers to the electrical charge of the ion in a solution.