Understanding Literacy & Numeracy

Literacy, numeracy, and technology skills are increasingly important in today’s information-rich environments. What people know and what they do with what they know have a major impact on their life chances. For example, people with lower literacy skills are more likely than those with better literacy skills to report poor health.

Apple sitting on a stack of books next to a laptop.

People need literacy and numeracy skills to find, understand, and use health information and services.

The resources on this page explain literacy and numeracy, describe how they’re measured, and provide literacy and numeracy data. You’ll also find links to resources that discuss literacy policies and practices, and ideas about how to promote literacy and numeracy.

What Are Adult Literacy and Numeracy?

The U.S. Department of Education defines adult literacy and numeracy in terms of skills that help people accomplish tasks and realize their purposes. Researchers can measure literacy and numeracy skills, but skills are not static. People can build their skills, and even adults with limited skills can get better results when their environments accommodate the skills they have.

  • Literacyexternal icon is understanding, evaluating, using, and engaging with written text to participate in the society, to achieve one’s goals and to develop one’s knowledge and potential.
  • Numeracyexternal icon is the ability to access, use, interpret, and communicate mathematical information and ideas, to engage in and manage mathematical demands of a range of situations in adult life.

Population Measures of Literacy, Numeracy, Health Literacy Skills and Technology Use

Community Health Literacy Assessment

In 2018, researchers at the Herschel S. Horowitz Center for Health Literacy at the University of Maryland developed the Community Health Literacy Assessment (CHLA) questionnaireexternal icon. The CHLA captures data in three areas:

  • A community’s health literacy assets and activities
  • A community’s health literacy gaps
  • A community’s health literacy opportunities

In 2021, the researchers reported resultsexternal icon of interviews conducted using the CHLA. The researchers recommend that others replicate the CHLA framework to capture health literacy data during community health assessments.

Adult Health Literacy Skills

The U.S. Department of Education collects and reports data adult literacy and numeracy skills. In 2006, they published the only national data on health literacy skills. These studies found that adults who self-report the worst health also have the most limited literacy, numeracy, and health literacy skills.

Youth Literacy Skills

The Department of Education also collects and reports data on school-aged children and youth. Elementary school children with weak literacy and numeracy skills often struggle academically through the middle and high school years. Research shows that academic success, risky behaviors and health status are linked.

Data on Adults’ Literacy and Numeracy Skills

The most current adult literacy data come from the Program for the International Assessment of Adult Competenciesexternal icon, a 24-country comparative study. This study assessed adults’ proficiency in three domains: literacy, numeracy, and problem-solving in technology-rich environments. Below we present select findings on literacy and numeracy.

In each of these domains, adults perform tasks with different levels of complexity. Their skills with these tasks are quantified and categorized into “proficiency levels.” The proficiency level “below level 1” is the lowest level and “level 5” is the highest proficiency level. If they can perform the most complex tasks, they are rated as having proficient skill.

Only 12% of U.S. adults scored in the highest literacy proficiency levels, and only 9% scored in the highest numeracy levels.

PIAAC* literacy scale pie chart. Below level 1: 4 percent. Level 1: 14 percent. Level 2: 34 percent.Level 3: 36 percent.Level 4/5: 12 percent.

Figure 1: Percentage of U.S. adults age 16 to 65 at each level of proficiency on the PIAAC literacy scale

PIAAC* numeracy scale pie chart.  Below level 1: 10 percent. Level 1: 20 percent. Level 2: 34 percent.Level 3: 27 percent.Level 4/5: 9 percent.

Figure 2: Percentage of U.S. adults age 16 to 65 at each level of proficiency on the PIAAC numeracy scale


Below you will find other research studies on literacy, numeracy, and related skills and knowledge.

  • Adult Literacy Research Centerexternal icon (Georgia State University)
    This website describes one of several U.S. Department of Education funded research centers. It also provides literacy resources and information about readability.
  • Literacy.orgexternal icon
    This web site is a resource on research and development on literacy in the U.S. and worldwide. (University of Pennsylvania, Graduate School of Education)
  • The Longitudinal Study of Adult Learningexternal icon (Portland State University)
    The Longitudinal Study of Adult Learning project addresses key questions about the literacy development, learning and life experiences of low-education adults over time.

Policy, Practice, and Promotion

This section contains important links that discuss literacy and numeracy policies and practices and ideas about how to promote literacy and numeracy.


Page last reviewed: September 1, 2021