mEq to mg Calculator
Potassium (K+)
Sodium (Na+)
Calcium (Ca2+)
Magnesium (Mg2+)
Chloride (Cl-)
Potassium Chloride (KCl)
Sodium Chloride (NaCl)
Sodium Bicarbonate (NaHCO3)
Custom (Enter Weight & Valence)
Conversion Result:
var substanceSelect = document.getElementById('substanceSelect');
var customInputs = document.getElementById('customInputs');
substanceSelect.onchange = function() {
if (this.value === 'custom') {
customInputs.style.display = 'block';
} else {
customInputs.style.display = 'none';
}
};
function calculateMg() {
var meq = parseFloat(document.getElementById('meqValue').value);
var weight, valence;
if (isNaN(meq)) {
alert('Please enter a valid mEq amount');
return;
}
if (substanceSelect.value === 'custom') {
weight = parseFloat(document.getElementById('customWeight').value);
valence = parseFloat(document.getElementById('customValence').value);
} else {
var parts = substanceSelect.value.split('|');
weight = parseFloat(parts[0]);
valence = parseFloat(parts[1]);
}
if (isNaN(weight) || isNaN(valence) || valence <= 0) {
alert('Please provide valid Atomic Weight and Valence values.');
return;
}
// Formula: mg = (mEq * Atomic Weight) / Valence
var result = (meq * weight) / valence;
var resultDisplay = document.getElementById('mgResult');
resultDisplay.innerHTML = result.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2}) + ' mg';
document.getElementById('resultArea').style.display = 'block';
}
Understanding mEq to mg Conversion
In clinical pharmacy and chemistry, milliequivalents (mEq) and milligrams (mg) are standard units used to measure electrolytes and medications. While milligrams measure the absolute mass of a substance, milliequivalents measure the chemical activity or "combining power" of an ion.
The Conversion Formula
To convert from mEq to mg, you must know the molecular weight of the substance and its valence (the electric charge of the ion). The mathematical formula is:
mg = (mEq × Atomic or Molecular Weight) / Valence
Key Terms Explained
- mEq (Milliequivalent): One-thousandth of an equivalent. It represents the amount of a substance that will react with or supply one millimole of hydrogen ions.
- Atomic/Molecular Weight: The sum of the atomic masses of the atoms in a molecule (e.g., Sodium is approximately 23 g/mol).
- Valence: The number of electrons an atom must lose or gain to achieve a stable electronic configuration (e.g., Calcium has a valence of 2).
Common Conversion Examples
| Substance | Conversion for 10 mEq |
|---|---|
| Potassium Chloride (KCl) | 745.5 mg |
| Sodium Chloride (NaCl) | 584.4 mg |
| Magnesium (Mg2+) | 121.5 mg |
How to Use the Calculator
- Enter the amount of mEq you wish to convert.
- Select the specific Substance from the dropdown menu (e.g., Sodium or Potassium Chloride).
- If your substance isn't listed, choose "Custom" and manually enter its molecular weight and valence.
- Click "Calculate" to see the result in milligrams.
Why is this Conversion Important?
In medical settings, dosages for electrolytes like Potassium or Magnesium are often prescribed in mEq. However, pharmaceutical manufacturing often lists the mass in mg. Accurate conversion is vital to ensure patient safety and proper electrolyte balance in intravenous (IV) fluids and oral supplements.