What is another word for guesstimating?
Pronunciation: [ɡˈɛstɪmˌe͡ɪtɪŋ] (IPA) 
Guesstimating, a blend of the words guessing and estimating, is a commonly used informal term that refers to making an approximation or rough estimate. However, there are several synonyms that one can use instead of guesstimating to express the same idea more formally. These synonyms include approximating, estimating, calculating, reckoning, conjecturing, surmising, supposing, and speculating. Each of these words has a slightly different connotation and may be used in specific contexts. For instance, approximating and estimating are commonly used in scientific research, whereas conjecturing and supposing are more suitable for personal relationships or informal conversations.
