Ecological footprint (EF) indices estimate the impact of an individual's lifestyle on the planet by converting levels of consumption into the amount of land needed to sustain production levels and lifestyle choices. Several popular organizations (e.g. WWF, Global Footprint Network) now offer personalized EF calculators to help inform consumers of the impacts of their personal consumption habits. In this paper, we evaluate the most popular online EF calculators and find that, even when the most environmentally friendly options are adopted, for the majority of available indices, one still exceeds the planet's biocapacity levels. The absence of options to fully offset one's environmental impacts implicitly suggests that there is no truly sustainable level of consumption at current population levels, even under the most prudent consumer choices. Although all online EF calculators claim to be a tool for education to promote sustainable behaviour, their calculations suggest, to the contrary, that as consumers we may postpone but not necessarily prevent environmental catastrophes. © 2010 John Wiley & Sons, Ltd. and ERP Environment.