Blood Serum Urine Osmolarity Osmolality Calculator free online for calculation of
chemicals dissolved in the serum/blood/urine. Chemicals that affect the osmolality test include sodium, chloride, bicarbonate, proteins, and sugar (glucose).
Formulas Used: Osmolality = (2 x (Na+K)) + (BUN/2.8) + (Glucose/18)
where,
Na – Sodium
K – Potassium
BUN – Blood Urea Nitrogen
Glu – Glucose/sugar
Osmolality vs Osmolality in urine
The main difference: Osmolality is based on mass (\(kg\)) of solvent, while osmolarity is based on volume (\(L\)) of the solution.
Why they are used interchangeably for urine: Because urine is mostly water, one liter of water has a mass of about one kilogram. This makes the numerical difference between osmolality and osmolarity negligible for most practical purposes in medicine.
Which is more accurate: Osmolality is the more precise measure because the mass of the solvent (water) does not change with temperature, while the volume does.
Why both are used: Osmolality is the preferred measure for accuracy, but osmolarity is often more practical for calculations and measurements in liters.
Urine Osmolality Calculator
Urine Osmolality Calculator
Note: This is a calculated estimate of urine osmolarity. The terms osmolarity (mOsm/L) and osmolality (mOsm/kg) are often used interchangeably in clinical practice for diluted body fluids like urine, but a laboratory measurement provides the true osmolality.
