Osmolal Gap Calculator
Difference between measured and calculated serum osmolality.
Your result
A gap above about 10 mOsm/kg is abnormal and can occur with some toxic alcohols or other unmeasured solutes. Interpret it alongside the clinical picture.
Medical disclaimer: This tool is for education and is not medical advice. Read more.
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Frequently asked questions
What does the Osmolal Gap Calculator do?
Difference between measured and calculated serum osmolality. Enter your values and the result and chart update instantly.
How accurate is it?
It uses published, widely used formulas. Results are estimates for education and planning, not a diagnosis. Talk to a qualified clinician about decisions affecting your health.
Is my information stored or shared?
No. All calculations run in your browser and nothing you type is sent to a server or saved.
What can I search to find this tool?
People find it by searching for: osmolar gap; osmol gap toxic alcohol; calculated osmolality.