Wages are the main determinant of living standards for the vast majority of workers and families around the world. This manual describes a new methodology to measure what constitutes a decent but basic standard of living and how much workers need to earn to afford this, making it possible for researchers to estimate comparable living wages around the world and determine gaps between living wages and prevailing wages. The new, practical methodology in this manual draws on 10 years of research and experience to clearly explain each step in the estimation process, based on standards for a low-cost nutritious diet, healthy housing, and all other needs including decent health care and children's education. It stresses transparency and the need for time- and place-specific living wage estimates, and is replete with examples from country studies that have put it to the test. The authors describe how living wages can be estimated in locations and countries where secondary data are limited and make new, practical recommendations on how to value in kind benefits as partial payment of a living wage An essential tool for global sustainability standards, researchers, NGOs, governments and international organizations interested in wages, estimating realistic poverty lines, formulating policies for reducing poverty and income inequality, and improving livelihoods and international trade agreements. This manual is also an excellent tool for companies, global sustainability standards, trade unions, NGOs, and public-private partnerships, and others concerned with corporate social responsibility and human resources.