Definition
The Adjusted Cohort Graduation Rate (ACGR) is the standardized federal metric used to measure the percentage of public high school students who graduate with a regular diploma within four years of entering the ninth grade. The cohort is 'adjusted' because it tracks a specific group of students over time—adding students who transfer into the school during grades 9 through 12, and subtracting students who transfer out, emigrate, or die.
How K12 Atlas uses it
K12 Atlas includes school-level and district-level ACGR percentages as a core academic context field. By presenting the actual cohort size along with the graduation rate, the dataset allows users to understand how many students graduated out of the specific class, rather than looking at a raw percentage in isolation.
Source caveats
Graduation rates are reported by state Departments of Education and EDFacts. Since state-level rules for what constitutes a 'regular high school diploma' can differ (e.g., how vocational or special-education diplomas are counted), ACGR percentages are not always perfectly comparable across state lines. Additionally, states publish graduation cohorts on a lag, typically releasing figures several months after the school year ends.
Implementation rule
To prevent statistical distortion, K12 Atlas displays the cohort size next to the graduation rate. If a school has a small cohort (e.g., fewer than 10 students), a single student's outcome can swing the rate by 10% or more. The data pipeline also retains the 'estimated' flag where federal reporting standards suppress exact percentages to protect student privacy.
Organic role
This glossary entry helps users understand on-time high school completion metrics. From here, users can navigate to the national graduation rate data story, find state-level aggregates, or check glossary terms for other federal sources.
What not to infer
An ACGR percentage is not a school rating or a proxy for student success. A lower rate can reflect high student mobility, local economic factors, or alternative pathway programs. K12 Atlas maintains an objective presentation and strictly discourages using ACGR for steering or school-ranking purposes.
Related buyer path
School-level graduation rates and class sizes are available in our District Reports, State Packs, and National Sheets. Users can download the free Austin ISD sample to see how cohort sizes and graduation rates are structured with source attributions.