Milliequivalents (mEq), Millimoles (mmol) & Milliosmoles (mOsm) Calculator
Converts electrolyte mass (mg) into mmol, mEq, and theoretical mOsm using molecular weight, valence, and dissociation count.
⚠️ Educational Calculation & Clinical Safety Safeguard: HIGH-ALERT: Concentrated Potassium Chloride (KCl) for injection must ALWAYS be diluted prior to IV infusion (peripheral rate typically ≤10 mEq/hr). Educational calculations do not replace clinician assessment, patient-specific laboratory monitoring, or institutional prescribing protocols.
Interactive Calculator
Allowed physiological/compounding range: 1 to 100000 mg
Allowed physiological/compounding range: 1 to 2000 g/mol (mg/mmol)
Allowed physiological/compounding range: 1 to 4 valence (1, 2, or 3)
Allowed physiological/compounding range: 1 to 5 particles
Calculated Output (mEq (plus mmol & mOsm))
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Step-by-Step Mathematical Derivation & Explanation:
Validated Formula & Conversion Rules
mmol = Mass (mg) / MW; mEq = (Mass (mg) × Valence) / MW; mOsm = mmol × iWorked Clinical Example
Potassium Chloride (KCl, MW = 74.5, valence = 1, i = 2 ions): 745 mg KCl = 745 / 74.5 = 10.0 mmol = 10.0 mEq = 20.0 mOsm.
Rounding Rules, Clinical Interpretation, Assumptions & Known Limitations
- 1. Purpose: Converts electrolyte mass (mg) into mmol, mEq, and theoretical mOsm using molecular weight, valence, and dissociation count.
- 2. Required Inputs & Validated Units: Electrolyte Mass (mg, range 1–100000), Molecular Weight (MW) (g/mol (mg/mmol), range 1–2000), Ionic Valence (valence (1, 2, or 3), range 1–4), Number of Dissociated Ions (i) (particles, range 1–5)
- 3. Output Unit:
mEq (plus mmol & mOsm) - 4. Result Interpretation Notes: Converts electrolyte mass (mg) into millimoles (mmol), milliequivalents (mEq), and theoretical milliosmoles (mOsm).
- 5. Rounding Guidance: Round mEq and mmol to 1 or 2 decimal places.
- 6. Mathematical & Clinical Assumptions: Assumes complete ideal ionic dissociation in dilute aqueous solution.
- 7. Known Limitations & Contraindications to Formula Use: Real osmotic pressure (osmolality) in concentrated parenteral nutrition bags is slightly lower than theoretical osmolarity due to inter-ionic attraction.
- 8. Supporting Compendial & Clinical References: Indian Pharmacopoeia (IP 2022), National Formulary of India (NFI), British National Formulary (BNF), and NCBI Bookshelf Clinical Pharmacology Compendia.