Solution Osmolarity
Calculator
Results
- Osmolarity (Osm/L)
- 0.308
- Osmolarity (mOsm/L)
- 308
- Dissolved particle concentration (mmol/L)
- 308
Biology and lab results
| Osmolarity (Osm/L) | 0.308 |
| Osmolarity (mOsm/L) | 308 |
| Dissolved particle concentration (mmol/L) | 308 |
formula-map diagram
- Osmolarity (Osm/L)
- 0.308
- Osmolarity (mOsm/L)
- 308
- Dissolved particle concentration (mmol/L)
- 308
Formula breakdown
Formula
osmolarity = molarity × i (particles per formula unit)= 0.308
Note
Simplified model: these results use standard textbook laboratory relationships and average constants (A260 = 1 for 50 µg/mL dsDNA, 617.96 g/mol per base pair, ~110 Da per amino acid, ideal exponential growth). Real samples vary with purity, contaminants, buffer, temperature and instrument calibration. Always confirm against your own standards and protocol; do not use for diagnostic or safety-critical work.
More in Biology and lab
See all →Frequently asked questions
What is osmolarity and how does it differ from molarity?+
Molarity counts moles of solute per liter of solution regardless of how the solute behaves in water, while osmolarity counts the total moles of dissolved particles per liter, accounting for the fact that some solutes dissociate into multiple particles (like NaCl into Na+ and Cl-) and therefore contribute more osmotically active particles than their molarity alone suggests.
How is osmolarity calculated from concentration and dissociation?+
Osmolarity = molarity x number of dissociated particles (the van 't Hoff factor, i), so a 1 M solution of NaCl (which dissociates into 2 ions) has an osmolarity of about 2 Osm/L, while a 1 M solution of glucose (which does not dissociate) has an osmolarity of 1 Osm/L.
Why does osmolarity matter for cell biology and IV solutions?+
Cells and tissues are sensitive to the osmotic pressure difference across their membranes; an isotonic solution matches the osmolarity inside cells (roughly 275-295 mOsm/L for human plasma) so cells neither swell nor shrink, which is why IV fluids are formulated to a specific osmolarity target.
What is the difference between osmolarity and osmolality?+
Osmolarity is osmoles of solute per liter of solution, while osmolality is osmoles per kilogram of solvent (usually water); they are numerically very close for dilute aqueous solutions but diverge for concentrated solutions since osmolarity is affected by the total solution volume, including the solute itself.
Why might a calculated osmolarity not match a measured (osmometer) value?+
The calculation assumes ideal, complete dissociation, but in real, especially concentrated, solutions ions interact with each other and do not behave as fully independent particles (a deviation captured by the osmotic coefficient), so measured osmolality from an osmometer is often somewhat lower than the theoretical calculated value.