This paper quantifies the factors contributing to Australia’s gender gap in superannuation balances. Around 60 per cent of the gap can be attributed to the prior stock of superannuation, for respondents who had superannuation balances in both 2014 and 2018 in the Household Income and Labour Dynamics in Australia Survey. This is partly due to the accumulation of the prior gap with investment returns. Financial literacy and risk aversion explain around 7 per cent of the gap in total, such as through impacts on subsequent investment returns. Work patterns and wage rates affect contributions and explain approximately 30 per cent of the superannuation gap in total.