Global comparisons and large samples are needed to inform policy makers about aging trends among people aged older than 60 years. Using harmonized data gathered from the Gateway to Global Aging data, we introduce a new framework to measure healthy aging across 13 OECD countries. First, we developed an original measure of physiological age (PA), that is, a measure of age weighted for the influence of frailty, activities of daily living limitations, and comorbidities. Second, we compared healthy aging measures across 13 countries based on a ranking of the countries according to the discrepancy between estimated PA and chronological age (CA). Third, we explored the socioeconomic factors associated with healthy aging. We found a strong correlation between our PA measure and biological age. Italy, Israel, and the United States are the 3 countries where PA is the highest (independent of CA), thus indicating aging in poor health. In contrast, Switzerland, The Netherlands, Greece, Sweden, and Denmark have much lower PA than CA, thus indicating healthy aging. Finally, the PA-CA discrepancy is higher among poorer, less educated, and single older individuals. Countries with higher PA need to implement or reinforce healthy aging measures and target the disadvantaged populations.