Magnesium (Mg) Unit Converter

MedFinal Seamless Index

Magnesium (Mg) is the fourth most abundant mineral in the body and a vital intracellular cation. It serves as a necessary cofactor for over 300 enzyme systems, playing crucial roles in nerve signaling, muscle contraction, energy production, and maintaining cardiac electrical stability.

Clinically, serum Mg levels are monitored in patients with kidney disease, diabetes, or those receiving intravenous fluids. Magnesium abnormalities often mirror or exacerbate other electrolyte imbalances (potassium, K, and calcium, Ca). Hypomagnesemia (low Mg) can lead to dangerous cardiac arrhythmias, while Hypermagnesemia (high Mg) can cause muscle weakness and respiratory depression. This converter facilitates switching between the SI unit (mmol/L) and the conventional mass unit (mg/dL).

SI Units / Molar

Recommended

mmol/L

µmol/L

Millimoles per liter (Standard International).

Conventional Units / Activity

mg/dL

mEq/L

g/L

mg/L

Clinical Context

Reference Range (Serum): Typically 1.7 – 2.5 mg/dL (0.70 – 1.03 mmol/L).

Magnesium (Mg) is divalent (valence Z = 2). The conversion factors are based on molecular weight (MW) 24.305 g/mol:
• Molar to Mass: 1 mmol/L ≈ 2.4305 mg/dL
• Molar to Activity: 1 mmol/L = 2 mEq/L
1 mEq/L ≈ 1.215 mg/dL.

Clinical References

How to Use This Calculator

Follow these steps to get accurate clinical conversions instantly.

Enter Values

Input your laboratory results into the corresponding unit field (e.g., mg/dL). You can use either dot or comma decimals.

Automatic Conversion

The calculator works in real-time. Conversions cover molarity (mmol/L) and activity (mEq/L), as well as mass-based units (mg/dL, g/L, mg/L).

Verify Units

Check the SI Units section. For divalent magnesium (Mg, valence 2), mEq/L is twice the numerical value of mmol/L (mEq/L = mmol/L × 2).

Reset

Use the Clear button to reset all fields before starting a new calculation.

? Frequently Asked Questions & Tips

How is mEq/L related to mmol/L?

For divalent ions like magnesium (Mg, valence 2), mEq/L = mmol/L × 2. Conversely, mmol/L = mEq/L / 2.

What is the conversion factor for mg/dL to mmol/L?

To convert mg/dL to mmol/L, divide by the atomic weight (24.305) and multiply by 10: mmol/L ≈ mg/dL × 0.411.

Disclaimer: This calculator is provided for educational and reference purposes only. It is not intended for clinical diagnosis, treatment, or medical decision-making. Always consult a qualified healthcare professional and refer to your laboratory’s official reference ranges before interpretation.

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