Shehroz Khan's answer to What are some machine learning algorithms I can learn without calculus? - Quora

Calculus is not prerequisite to learn a lot of ML algorithms such as KNN, Naive Bayes, Decsion Trees, Random Forest, boosting etc and similar methods. However, if you wanna go the route for neural nets or deep learning, you need to figure out calculus because algorithms such as backpropagation uses them a lot. Also Gradient boosting and similar type of algorithms will require calculus knowledge.