eValuator is a free scientific calculation tool to quickly evaluate an arbitrary expression, using an algebraic form. You can combine a range of functions with up to 6 variables. The latest CODATA 2018 and IAU 2012 and 2015 fundamental and astronomical constants are included.

You can elect to use c.g.s. units (common in astrophysics) or the more standard S.I. Units.

eValuator for OS X is designed as a floating utility window that can be allowed to float in front of all apps for easy access anywhere, or run as a normal window if desired. An auxiliary panel of keypads is given to help write expressions, although it can be operated entirely with the normal keyboard.

eValuator works with OS X 10.9 or newer include current systems. In addition, eValuator is completely sandboxed, and does not access the network or any key areas of the system.

Easy to use:
- Enter any algebraic expression, using any set of the variables, numbers, the operators and functions below, and any of the builtin constants.
- Optionally set up any of up to 6 variable values: x, y, z, t, a, or b.
- The expression is evaluated as you type, with the answer appearing at the top.
- There is no need for enter/return or equals buttons.
- Green indicates a valid expression and answer.
- The answer may be selected, copied, or shared as needed.
- Expressions and any constants or notes can be saved in the scrapbook memory system
- Compact, works well even on modest screens
- Can optionally float above all other windows or not as best fits the user's needs.