In addition, schools are taking aggressive action, such as hiring intervention specialists who work with students one on one, to keep teenagers in class, researchers said.
Growth in rates among African-American and Hispanic students helped fuel the gains. Most of the growth has occurred since 2006 after decades of stagnation.
"At a moment when everything seems so broken and seems so unfixable ... this story tells you something completely different," said John Gomperts, president of America's Promise Alliance, which was founded by former Secretary of State Colin Powell and helped produce the report.
Education Secretary Arne Duncan said Monday the country owes a debt of gratitude to teachers, students and families whose hard work helped the country reach the 80 percent mark.
"But even as we celebrate this remarkable achievement, our students have limitless potential and we owe it to all of our children to work together so they all can achieve at higher levels," Duncan said in a statement.
The rate of 80 percent is based on federal statistics primarily using a calculation by which the number of graduates in a given is year divided by the number of students who enrolled four years earlier. Adjustments are made for transfer students.
In 2008, the Bush administration ordered all states to begin using this method. States previously used a wide variety of ways to calculate high school graduation rates.
Iowa, Vermont, Wisconsin, Nebraska and Texas ranked at the top with rates at 88 percent or 89 percent. The bottom performers were Alaska, Georgia, New Mexico, Oregon and Nevada, which had rates at 70 percent or below.
Idaho, Kentucky and Oklahoma were not included because these states received federal permission to take longer to roll out their system.
The new calculation method allows researchers to individually follow students and chart progress based on their income level. By doing so, researchers found that some states are doing much better than others in getting low-income students — or those who receive free or reduced lunch meals — to graduation day.
Tennessee, Texas, Arkansas and Kansas, for example, have more than half of all students counted as low income but overall graduation rates that are above average. In contrast, Minnesota, Wyoming and Alaska have a lower percentage of low-income students but a lower than average overall graduation rate.
Graduation rates increased 15 percentage points for Hispanic students and 9 percentage points for African American students from 2006 to 2012, with the Hispanic students graduating at 76 percent and African-American students at 68 percent, the report said. To track historic trends, the graduation rates were calculated using a different method.
Also, there were 32 percent fewer "dropout factories" — schools that graduate less than 60 percent of students — than a decade earlier, according to the report. In 2012, nearly one-quarter of African-American students attended a dropout factory, compared with 46 percent in 2002. About 15 percent of Hispanic students attended one of these schools, compared with 39 percent a decade earlier. There were an estimated 1,359 of these schools in 2012.
Robert Balfanz, a researcher with the Everyone Graduates Center at the School of Education at Johns Hopkins University who was a report author, said some of these schools got better. Other districts closed these schools or converted them to smaller schools or parents and kids voted with their feet and transferred elsewhere.