https://www.amazon.co.uk/FX-991EX-Advanced-Scientific-Calcul... (£20)
Pretty sure most of my physics degree class used an FX-83.
For calculus, that's not so good. To have any intuition about calculus you need to be really proficient at algebra and graphing--by hand.
When you apply calculus in engineering and physics, sure, use the calculator. But when it's just calc, it really needs to be structured to be able to be done by hand.