What is the average length of tenure for a head of school?

Leadership sustainability is vital for a school's long-term success.  The average tenure for independent school headship has declined from 9.9 in 2012 to 6.9 years in 2020.  According to the National Association of Independent Schools, if current trends continue, one in five new heads who begin their headship in 2021-2022 will leave after three years or less.  Instability in school leadership can impact everything from enrollment, to fundraising, to faculty attrition.  Understanding head tenure trends can prepare schools to face leadership transitions more effectively.