Osmcalc

Osmcalc is a software tool and library designed to calculate osmolarity, osmolality, and related properties of aqueous solutions. It is used in research and clinical settings to assess solution tonicity, plan intravenous fluid formulations, and model cellular responses to solutes. Osmcalc supports calculations for a wide range of solutes, including electrolytes, sugars, and other compounds that may dissociate or associate in solution.

Calculation methods: The tool uses established relationships such as osmolarity (Osm/L) approximately equals the sum of solute molar concentrations, adjusted by the van't Hoff factor i; osmolality (mOsm/kg) similarly uses molality. It can incorporate temperature (for osmotic pressure) and handle dissociation into ions; some implementations offer corrections for non-ideal behavior at higher concentrations using activity coefficients. Mixed solutes and polyelectrolytes can be handled by summing contributions or by user-specified factors.

Features: supports multiple platforms, either as a command-line tool, web interface, or programming library (API). Accepts input as mass, molarity, or molality; supports unit conversions; allows user-defined solutes and dissociation factors; provides output in tables and can export CSV or JSON.

History/availability: Osmcalc is available from various providers and may be distributed as open-source software or commercial tools depending on the platform. Its design aims to be transparent and interoperable with standard chemical and biological computation workflows.

See also: Osmolarity, Osmolality, van't Hoff equation.