Ghana has been ranked last in the biggest global school rankings published by the OECD (Organisation for Economic Co-operation and Development).
Singapore was ranked first, while four other Asian countries were in the first five.
The analysis, based on test scores in maths and science in 76 countries, is a much wider map of education standards than the OECD's Pisa tests, which focus on more affluent industrialised countries. The latest Pisa test in 2012 polled 65 countries and regions.
OECD's education director Andreas Schleicher said: "This is the first time we have a truly global scale of the quality of education." The OECD economic think tank says the comparisons show the link between education and economic growth.
"The idea is to give more countries, rich and poor, access to comparing themselves against the world's education leaders, to discover their relative strengths and weaknesses, and to see what the long-term economic gains from improved quality in schooling could be for them," said Mr Schleicher.
Singapore is the top performer but it had high levels of illiteracy into the 1960s, he added, showing how much progress could be made.
The rankings are based on a combination of international tests taken in different regions, putting developed and developing countries on a single scale. The report, published by the OECD, argues that the standard of education is a "powerful predictor of the wealth that countries will produce in the long run". It also wrote: "Poor education policies and practices leave many countries in what amounts to a permanent state of economic recession."
This latest league table, ranking more than a third of the world's nations, also highlights the decline of Sweden - ranked 35th - with the OECD warning last week that it had serious problems in its education system. The United Kingdom came in 20th place, among higher achieving European countries, with the United States in 28th.
The findings will be formally presented at the World Education Forum in South Korea next week, where the United Nations is to convene a conference on targets for raising global education by 2030.