In most countries, wealth inequality is much higher than income inequality, spurring debates about wealth taxation. However, it is unclear if voters are aware of these differences. In a large scale survey experiment among a representative Dutch population (N=4,359), we study voters' perceptions of income and wealth distributions, and connect their views to administrative data about their own income and wealth. Despite a primer on the definition of income and wealth, respondents underestimate the  difference in inequality on the two measures by a factor of 10. Moreover, they use information about the income distribution to make predictions about the wealth distribution and vice versa, even when information about both is provided. An information intervention about actual inequality levels and personal ranks in the income/wealth distribution has an impact on the perceived inequality and perceived fairness, but little effect on policy preferences. Thus, voters  differentiate little between wealth and income distributions. We discuss implications for political debates about inequality and wealth taxation.