Mental states (beliefs, emotions, moods, desires, etc.) towards things can fit or fail to fit those things. Perhaps actions can fit or fail to fit the situations in which they are done. This paper explores whether having fitting mental states and doing fitting actions can constitute additions to a person’s well-being. The paper first discusses the desire-fulfilment theory of well-being. Then the paper considers hedonistic theories of well-being and criticises the recent proposal from Rossi and Tappolet that well-being consists only in fitting happiness. Then the paper turns to the objective list theory of well-being and Badhwar’s Aristotelian theory. In this context, the paper considers Bruno-Niño’s recent argument for fitting attitudes as a part of well-being. Finally, the paper explores whether, on the objective list theory and Badhwar’s theory, doing fitting actions constitutes an element of well-being. The upshots are that fittingness is not an element of well-being according to some theories of well-being and that it is an element of well-being either contingently or necessarily according to other theories of well-being.