Spending on tertiary education is defined as the total expenditure on the highest level of education, covering private expenditure on schools, universities, and other private institutions delivering or supporting educational services. The measure is a percentage of total education spending. At the tertiary level educational institutions in OECD countries are mainly publicly funded, although there are substantial and growing levels of private funding. At this level, the contribution to the costs of education by individuals and other private entities is more and more considered an effective way to ensure funding is available to students regardless of their economic backgrounds. “Households” refers to students and their families. "Other private entities" include private businesses and non-profit organisations, such as religious organisations, charitable organisations, and business and labour associations. Expenditure by private companies on the work-based training of apprentices and students is also taken into account, together with spending on research and development by educational institutions. Subsidised funding data available only for 2012.

Public spending on education includes direct expenditure on educational institutions as well as educational-related public subsidies given to households and administered by educational institutions. This indicator is shown as a percentage of GDP, divided by primary, primary to post-secondary non-tertiary and tertiary levels. Public entities include ministries other than ministries of education, local and regional governments, and other public agencies. Public spending includes expenditure on schools, universities and other public and private institutions delivering or supporting educational services. This indicator shows the priority given by governments to education relative to other areas of investment, such as health care, social security, defence and security. Education expenditure covers expenditure on schools, universities and other public and private institutions delivering or supporting educational services.

Private spending on education refers to expenditure funded by private sources which are households and other private entities. This indicator is shown as a percentage of GDP, divided into primary, primary to post-secondary non-tertiary and tertiary levels. Private spending on education includes all direct expenditure on educational institutions, net of public subsidies, also excluding expenditure outside educational institutions such as textbooks purchased by families, private tutoring for students and student living costs. Private spending includes expenditure on schools, universities and other public and private institutions delivering or supporting educational services.