Compatibilism at best but still determinismNo, they are not.
I have already shown how Calvin himself did not teach strict determinism but believed in both divine sovereignty and human volitional agency. Here are linked to other noted Calvinists doing the same.
Compatibilism (also known as soft determinism), is the belief that God's predetermination and meticulous providence is "compatible" with voluntary choice. In light of Scripture, human choices are believed to be exercised voluntarily but the desires and circumstances that bring about these choices about occur through divine determinism (see Acts 2:23 & 4:27-28). It should be noted that this position is no less deterministic than hard determinism - be clear that neither soft nor hard determinism believes man has a free will. Our choices are only our choices because they are voluntary, not coerced. We do not make choices contrary to our desires or natures. Compatibilism is directly contrary to libertarian free will. Therefore voluntary choice is not the freedom to choose otherwise, that is, without any influence, prior prejudice, inclination, or disposition. Voluntary does mean, however, the ability to choose what we want or desire most. The former view is known as contrary choice, the latter free agency. (Note: compatibilism denies that the will is free to choose otherwise, that is, free from the bondage of the corruption nature,for the unregenerate, and denies that the will is free from God's eternal decreee.) Compatibilism | Monergism
DIVINE CAUSAL DETERMINISM It should be conceded at the outset, and without any embarrassment, that Calvinism is indeed committed to divine determinism: the view that everything is ultimately determined by God. I will not argue this point—it can be amply documented from representative Calvinist sources—but will simply take it for granted as something on which the vast majority of Calvinists and their critics agree. To be more precise, I will assume that Calvinism is committed to divine determinism in the following sense: (DD) For every event E, God decided that E should happen and that decision was the ultimate sufficient cause of E.320 In other words, every event that occurs is willed by God, God’s willing an event is a sufficient cause of that event, and the divine will has no prior cause
Calvinism and the problem of evil pg 204.205
Nothing that exists or occurs falls outside God’s ordaining will. Nothing, including no evil person or thing or event or deed. God’s foreordination is the ultimate reason why everything comes about, including the existence of all evil persons and things and the occurrence of any evil acts or events.
b Talbot, "All the Good That Is Ours in Christ", in Suffering and the Sovereignty of God, ed. John Piper and Justin Taylor,
If God merely foresaw human events, and did not also arrange and dispose of them at his pleasure, there might be room for agitating the question, how far his foreknowledge amounts to necessity; but since he foresees the things which are to happen, simply because he has decreed that they are so to happen, it is vain to debate about prescience, while it is clear that all events take place by his sovereign appointment.
(John Calvin, Institutes of Christian Religion, Book 3, Chapter 23, Paragraph 6)