Osmolar Gap
Osmolar Gap: calculated with the published clinical method, with result interpretation. A reference tool that does not replace a doctor's advice.
ℹ Reference calculation based on the published method. It does not replace a clinical examination or a doctor's decision.
Osmolar Gap
Measured osmolalitymOsm/kg
Nammol/L
Glucosemmol/L
Ureammol/L
Osmolal gap
10mOsm/kg
Calculated osmolality
290mOsm/kg
Interpretation
Normal
More about: Osmolar Gap
What it calculates
The “Osmolar Gap” calculator computes Osmolal gap in mOsm/kg from 4 parameters: measured osmolality (mOsm/kg), na (mmol/L), glucose (mmol/L), urea (mmol/L).
Used by professionals and patients to assess health metrics, dosages, and risks.
Example calculation
With parameters Measured osmolality = 300 mOsm/kg, Na = 140 mmol/L, Glucose = 5 mmol/L, Urea = 5 mmol/L the result is 10 mOsm/kg (An elevated gap warrants ruling out methanol or ethylene glycol poisoning).
How to use
- Enter measured osmolality, na, glucose and urea — each field above is adjustable with a slider.
- Osmolal gap (mOsm/kg) is calculated automatically as you type.
- Check the worked example below to see the formula applied to real numbers.
- Copy the result or bookmark this calculator.
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FAQ
How is BMI calculated?
BMI = weight (kg) / height (m)². Example: 70 kg / (1.75 m)² = 22.9. The WHO normal range is 18.5–24.9; below that is underweight, 25–29.9 is overweight, and 30+ is obese.
Is BMI accurate for everyone?
No. BMI does not distinguish muscle from fat, so athletes may show a high BMI with low body fat. It is also less reliable for teenagers, pregnant people, older adults, and very tall or short individuals.
What are the BMI categories?
Underweight: below 18.5. Normal: 18.5–24.9. Overweight: 25–29.9. Obese class I: 30–34.9; class II: 35–39.9; class III: 40+.
What is a better measure than BMI?
Body fat percentage, waist-to-height ratio (aim for under 0.5), and waist circumference give a clearer picture of health than BMI alone.
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