Lifestyle changes are an essential, complementary measure for reducing greenhouse gas emissions and, therefore, also an important ingredient to climate policy. Computational models of lifestyle changes and their contribution to climate change mitigation can provide valuable insights in support of decision-making by individuals and policymaking. In this Perspective, we examine four modelling approaches with this in mind: input-output analysis, life cycle assessment, integrated assessment models, and agent-based models. They have different strengths and weaknesses related to spatial and temporal scales, sector representation, consumer heterogeneity, and impact assessment. Despite their differences, all are ultimately suitable for modelling different types of climate-friendly lifestyle changes – from sufficiency over efficiency to modal shift measures. Each modelling approach provides useful, albeit partial, insights into lifestyle changes. The identified challenges call for both continual refinements within individual model frameworks and hybrid methods that bridge their respective strengths and allow for representing lifestyle changes more comprehensively. Together, they inform about the theoretical mitigation potential, initiative feasibility, behavioural plasticity, and policy effectiveness of lifestyle changes. Ultimately, cross-disciplinary collaboration will be key to designing lifestyle-focused policies that are both impactful and acceptable.