Here is a breakdown of what you’ll actually find, including the "calculator" tools that are most helpful for engineers. There is no single official "CIBSE Calculator" app released by the institution itself. Instead, CIBSE publishes the official chart (Guide C, Chapter 1), and third-party developers build tools using that specific chart's data. The Most Helpful "Calculator" Tools If you search for that phrase, these are the results you want (ranked by usefulness):
That's a great term to search for, as the is the standard for HVAC design in the UK and many other regions following British standards. cibse psychrometric chart calculator
Use the official interactive chart at psych-chart.cibse.org for quick answers, and download the CIBSE Psychrometric Group Excel Add-in for real engineering work. Here is a breakdown of what you’ll actually