Rectangular Hollow Section beam calculator

This is solely an Euler-Bernoulli beam [Wikipedia] leading into simple "Moments sum to zero" calculator.

It knows nothing of design codes (eg the "EN 1990" series of the "Eurocodes").
What this calculator does is: [links are to Wikipedia]; {are the input variables}
  I {dimensions} → Z → Myy} → M=FL or M=FL/4 {L}

* Use SI units * You can use indicial notation
eg 123.45mm == 1.23453e-1m == 123.45e-3m

My calculation is based on a "sharp" right-angled-corner shape.
In the real world Rectangular Hollow Sections have curved corners.
The deviation caused by this from real sections is small - but there.

RHS Height
RHS Width
RHS Wall-thickness
RHS beam length
RHS material yield stress
RHS material Young's modulus

Authoritative tabulated data for commercial sections including important characteristic which cannot be readily calculated are presented as The Blue Book - Steel for Life [external link] which is considered a vital information for most working with steel.
The program might allow you to rapidly explore concepts, but The Blue Book - Steel for Life [external link] needs to be your reference.

(R. Smith, 24Jul2023, 03Aug2023 (title))