Work out osmolal gap instantly with clear inputs, formula shown and shareable results.
Subtracts the calculated osmolality from a measured value; the residual gap points to unmeasured osmoles such as methanol or ethylene glycol.
Osmolal gap
Calculated osmolality = 2 x Na + glucose/18 + BUN/2.8; gap = measured - calculated
Educational estimate only. Not a substitute for professional clinical judgement, and must not be used to make treatment or dosing decisions.
Above roughly 10 mOsm/kg is usually treated as raised, though normal values range from -10 to +10.
Yes. Add ethanol (mg/dL) / 3.7 to the calculated value when a known ethanol level is present.