For those seeking a replacement for the HP 32Sii calculator, options vary based on intended use. The Casio FX-115ES is recommended for general calculations. For graphing capabilities, the TI-Nspire series is suggested, though some users find its key arrangement less user-friendly. The HP35s is highlighted as a natural substitute, offering RPN functionality, scientific and programmable features, a two-line display, and a similar size to the HP 32Sii, all at an affordable price of around $60. It has received positive reviews on Amazon, making it a solid choice for users looking for a comparable model.