Slight differences in standard of living, issuing from horizontal inequalities between ethnic groups, are a predicate of ethnopolitical violence in Kenya. Developing and validating a scale to estimate the quality of life differences, between warring ethnic groups, can deepen our understanding of an important precursor of ethnopolitical conflict. From a careful review of poverty and developmental literature, the 16 items used in the Quality of Life Scale emerged. In subsequent exploratory factor analysis, a three-factor solution surfaced, and this was subjected to confirmatory factor analysis (CFA). The CFA model scale met the criteria for composite reliability, construct validity, and strict factorial invariance. The scale has enriched our understanding of the three latent dimensions of quality of life that matter most in characterizing the quality of life. First, the indicator "proud about your life" was the strongest factor for latent factor social and physical wellbeing. Second, “can save income”, a proxy for quality of employment. This was the leading indicator for latent factor disposable income. Third, and the indicator “house comfortable to live in” was the notable indicator of latent factor living standards. The Quality of Life Scale can track trends in quality of life of ethnic groups that have a history of ethnopolitical conflict in places like Mathare and Kibra. The scale can be used in other known hotspots of violence in Kenya too where ethnic groups are susceptible to ethnopolitical conflict borne of quality of life differences.