During the last 50 years, humanity’s Ecological Footprint has increased by nearly 190% indicating agrowing unbalance in the human-environment relationship, coupled with major environmental andsocial changes. Our ability to live within the planet’s biological limits requires not only a major re-think in how we produce and distribute‘things’, but also a shift in consumption activities. Footprintcalculators can provide a framing that communicates the extent to which an individual’s dailyactivities are compatible with our One Planet context. This paper presents thefindings from thefirstinternational study to assess the value of personal Footprint calculators in guiding individuals towardssustainable consumption choices. It focuses specifically on Global Footprint Network’s personalFootprint calculator, and aims to understand the profile of calculator users and assess the contributionof calculators to increasing individual awareness and encouraging sustainable choices. Our survey of4245 respondents show that 75% of users resided in 10 countries, 54% were aged 18–34 years and hadlargely used the calculator within an educational context(62%). The calculator was considered avaluable tool for knowledge generation by 91% of users, and 78% found it useful to motivate action.However, only 23% indicated the calculator provided them with the necessary information to makeactual changes to their life and reduce their personal Footprint. The paper discusses how and why thispersonal Footprint calculator has been effective in enhancing individuals’understanding of theenvironmental impact of their actions, framing the scale of the problem and empowering users tounderstand the impacts of different lifestyle choices. Those individual-level and system-level changesneeded to generate global sustainability outcomes are also discussed. Similar to other calculators, a gapis also identified in terms of this calculator facilitating individuals to convert new knowledge intoaction.