Informal carers report lower evaluative wellbeing than non-carers. In contrast to this literature and our own analysis of evaluative wellbeing, we find carers have a small but higher level of experienced wellbeing than non-carers do. To investigate why, we use decomposition analysis which separates explanatory factors into how time is used and how those uses of time are experienced. We analyze activities and associated experienced wellbeing measured in ten-minute intervals over two days by 4817 adults from the 2014/15 UK Time Use Survey. We use entropy balancing to compare carers with a re-weighted counterfactual non-carer group and then apply Oaxaca-Blinder decomposition. The experienced wellbeing gap of 0.066 is the net result of several substantial competing effects of time use. Carers experienced wellbeing would be higher by 0.188 if they had the same patterns and returns to time use as non-carers which is driven by sleep, time stress and alternative characteristics of time use. However, leisure and non-market activities serve to dampen this increase in experienced wellbeing. Initiatives to improve and assess carer wellbeing should pay close attention to how carers spend their time.