Calculates on is a term used to describe a process of estimation, prediction or planning. The opposite of calculative is spontaneous, which describes people or things that act without prior planning or intention. Antonyms for calculates on are guess or speculate. When we guess, we are making an assumption based on incomplete information. Speculating is similar to guessing, but is usually associated with financial or economic decisions. Meanwhile, trust is also an antonym to calculate, as trust refers to having faith or confidence in someone or something without needing to calculate or estimate its potential outcomes. Ultimately, the opposite of calculating on is a lack of calculation, whether it be through spontaneous action, guessing, or trusting.