Luckily, AIP has a survey for this as well! https://www.aip.org/sites/default/files/statistics/graduate/trendsphds-p-12.2.pdf https://www.aip.org/sites/default

Luckily, AIP has a survey for this as well! https://www.aip.org/sites/default/files/statistics/graduate/trendsphds-p-12.2.pdf https://www.aip.org/sites/default/files/statistics/graduate/... Only 3% of surveyed physics PhDs took 4 years, nobody took less and 6-7 years was average.