Three studies, 307 women, one pooled figure: a mean labia minora length of 53.23 mm — about 2.10 inches — with a 95% confidence interval running from 43.50 to 62.96 mm. Mean width came in at 18.28 mm (0.72 in), confidence interval 14.93 to 21.64 mm.

In 2015, researchers at King's College London pooled measurements from up to 15,521 men to build the reference nomograms still quoted in nearly every article about penile size. Buried in the methods section is a decision that says more about anatomical shape than the results ever could: the…