evidence: PSNI chief constables have averaged 5.2 years in post. Looking only at chief constables who finished their tenure this century, and at the 15 largest forces across the UK, we found that chief constables average 5.7 years in their role. The average tenure for such forces in England and Wales specifically is 5.8 years. For extra context, in the same period Garda Commissioners have averaged 4.1 years in position.