OsmoCalc About

OsmoCalc is a software package that is downloaded and run from your local computer to estimate the osmolality of liquid solutions fed to calves based on the content of osmotically active compounds in the liquid.

The primary driver of osmolality is lactose in most calf feeds.  Because lactose is not typically reported on most feed tags, the concentration of lactose is estimated as 100% minus the content of water, protein, fat, ash, and non-lactose carbohydrates.  High quality milk replacers (and whole milk) do not usually contain non-lactose carbohydrates, though the calculator allows adjustment of the amount of lactose for components such as starch or oligosaccharides.

OsmoCalc estimates osmolality as milliosmoles per kilogram (mOsm/kg) in the solution using the molar weight of lactose and macro-minerals.  Contribution from micro-minerals is generally small, but may be included in the osmolality estimates.  Contribution from water (in a calf milk replacer) may also be included in the calculation.

The program was developed in Visual Basic using VB.NET and built with Microsoft Visual Studio. It is designed as a Windows-based formulation tool that runs locally on the user’s computer, providing a responsive interface for osmolality calculations without reliance on cloud services or external databases. The software architecture combines a modern graphical user interface contributed by an osmolality gauge provided by Syncplicity as part of their community license feature.  The program contains typical composition of calf liquids such as milk replacer, water, and whole milk.

Version 1.0 of OsmoCalc was made available in February 2026.  Subsequent releases follow as needed for new features and bug fixes.  The program is free to use.