PurposePrevious research on age-related loyalty is sparse, contradictory and suffers from methodological limitations and criticisms. This study aims to apply two methodological advances to fresh purchasing data to give a much clearer picture of age-related differences in brand loyalty.Design/methodology/approachAn online brand choice survey (n = 1,862) is used to examine age-related loyalty within three low-involvement categories in New Zealand. The polarisation index (φ) is adopted as the measure of loyalty to control for confounding influences present in prior research. Results for chronological age are validated through comparison with results for measures of cognitive, biological and sociological age, as well as household life cycle.FindingsContrary to prior research, age-related differences in loyalty are detected in two of the three low-involvement categories studied. The third category does not show detectable loyalty for any age group. Although differences in brand loyalty are broadly present across all age measures, no alternative measure outperforms chronological age in detecting variations in age-related loyalty.Research limitations/implicationsTo the best of the authors’ knowledge, this is the first evidence that age-related brand loyalty is present in low-involvement categories. However, effects are small and easily obscured by confounding factors. More research is needed to determine how results vary by category.Practical implicationsDespite showing minor differences in loyalty, older consumers still purchase from a wide portfolio of brands and so should not be ignored by marketers. Future research can investigate loyalty for older consumers by adopting the method of analysing differences in polarisation (φ) for chronological age groups.Originality/valuePrevious contradictory findings and methodological concerns about measurement of age-related loyalty are resolved through use of the polarisation index (φ) as a measure of loyalty and by confirmation that chronological age performs as well as any other age measure.