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Calculating high school graduation rates: At a glance

As high schools move to the top of the reform agenda, educators have been scrutinizing one the most significant indicators of a high school’s performance: the rate of students who graduate. The attention is well-deserved—a high school diploma is the minimal qualification young people need to survive in today’s society.

But there is great debate in education research circles about how many students actually earn a diploma. Various reports cite national graduation rates as low as 70 percent and as high as 83 percent. The state picture is even more confusing: 36 states report graduation rates between 80 and 97 percent. Another source says the reality in these same states is 58–86 percent (Hall, 2005).

While statisticians argue about whose numbers are best, stakeholders at the school and district level are left wondering how big the problem is, where the problem lies, and more importantly, what they can do to help fix it.

  • Why it's hard to know how many students graduate. Few states and districts have systems in place to collect and report accurate, reliable information on graduation rates. At the same time, many states and districts rely on weak methods for calculating the number of diplomas, for example, by basing the graduation rate on the number of students who entered 12th grade in the fall, and thus not accounting for students who may have dropped out in 9th, 10th, or 11th grade. The result is that many published graduation rates tell only part of the story about how many students are graduating. Some states’ approaches misrepresent the true proportion of students receiving a standard diploma by more than 20 percentage points (Hall, 2005).

  • The best way to get the whole picture. In order to improve the quality of calculating and reporting graduation rates, the National Governors Association (NGA) developed the Graduation Counts Compact (2005). Under the Compact, states commit to developing a high-quality, student-level data collection system that tracks students from kindergarten through college. It also includes a four-year cohort graduate rate formula: The number of students who graduated divided by the number of students enrolling in 9th grade for the first time—plus the students who joined this class of students (that is, the cohort) and minus the students who left.

    For example,

    80 Graduates in 2006   x   100

    =

    72%   grad rate

    (100 9th graders  in 2002) + (20 transfers in) – (10 transfers out)

    All 50 states have signed the contract and promised to implement the reforms. However, at present fewer than half of the states have electronic student record systems that can follow individual students from pre-kindergarten through high school, and only a handful are using them to calculate a four-year cohort graduation rate (Education Week, 2006). It may take years for other states to get such systems in place.

  • The next best way—four-year estimates. In the absence of accurate student tracking systems, statisticians have developed a way of estimating graduation rates that produces a pretty good picture of how many students complete high school in four years. Enrollment-based graduation rate estimates rely on grade-by-grade enrollment counts from NCES’s Common Core of Data (CCD) to approximate how many 9th graders make it to graduation four years later. Advocates of this approach argue that even though these estimates cannot track individual students, they show how much a given class “shrinks” over time by examining how many 9th graders are enrolled one year, 10th graders the next year, 11th graders the next year, and so on.

Many recent high-profile reports on high school graduation are based on four-year estimates, most notably, the Manhattan Institute’s methodology, which calculates on-time graduation at about 70 percent (Greene, 2003).

It’s important to note that neither the four-year cohort nor the four-year estimate approach includes students who take five or more years to earn a diploma or students who earn alternate credentials like the GED or certificates of completion. For a complete picture of high school attainment, NGA recommends collecting and reporting these data as complementary rates to the four-year completion numbers.

What can districts do now to get a complete picture?

Local leaders do not need to wait until states have implemented the NGA contract. They can embark on their own changes now.

  • Delve into the data. In states that have yet to develop the capacity to track individual students and report a four-year cohort graduation rate, districts should closely examine the way their state and local graduation rates are collected, analyzed, and reported. Does the formula cover all four school years? How does the rate account for transfers? Dropouts?
  • Use complementary indicators. While a four-year cohort graduation rate is the most significant measure of completion, educators need to examine a variety of indicators like five- and six-year graduation rates, dropout rates, and in-grade retention rates in order to gain a full understanding of how their system is serving its students.
  • Strengthen documentation and tracking policies. Districts should require documentation for all student coding. If a student is coded as a transfer, for example, the school should have a transcript request from the receiving school. Districts should also mandate that all undocumented leavers be coded as dropouts. These policies would provide incentives for schools to improve their data collection and help produce a graduation rate that more accurately reflects the actual graduation rate.
  • Develop understanding. Districts should communicate to parents and other community leaders that they are taking responsibility for improving the reporting of graduation rates. Districts that get ahead of the issue typically get lauded, even when methodological changes cause a significant drop in the rate


This guide was prepared for the Center for Public Education by Ulrich Boser, a  freelance writer and a contributing editor at U.S. News and World Report. His work has appeared in Smithsonian, Slate, and the Washington Post.

Posted: June 23, 2006

©2006 Center for Public Education