Plus42 vs HydroCalc

Plus42 is an advanced scientific programmable calculator, based on Free42. Free42, in turn, is a complete re-implementation of the HP-42S scientific programmable RPN calculator, which was made from 1988 until 1995 by Hewlett-Packard. Free42 is a complete rewrite and contains no HP code whatsoever. Plus42 builds on Free42 and adds: Algebraic expressions modeled after those used on the HP-27S and HP-17B/19B; attached units and unit conversions modeled after those used on the HP-48/49/50 series; directories for more organized storage of programs and variables; a larger display, with 8 rows and 22 columns (131x64 pixels) by default, which the user may resize at will; time value of money and amortization schedules; and two-dimensional plotting of functions, with ability to zoom and pan, and find integrals and roots from points in the plot.

HydroCalc: Manning Flow is a fast, reliable tool for calculating open channel and pipe flow using the Manning equation. Designed for engineers, designers, and students, HydroCalc makes it easy to evaluate hydraulic conditions in the field or at your desk—without spreadsheets or manual calculations. Key Features • Compute flow, velocity, depth, slope, and hydraulic radius • Supports both open channel and circular pipe conditions • Flexible input options—enter known values and calculate the rest • Clean, intuitive interface for quick results • Works entirely offline—no internet connection required Built for Practical Use HydroCalc is designed with real-world applications in mind, including: • Stormwater design • Drainage analysis • Pipe flow evaluation • Open channel hydraulics Whether you’re checking a quick calculation in the field or verifying results during design, HydroCalc provides a dependable solution in seconds.