Does Size Matter? What the Research Actually Shows

Short answer: Girth matters more than length. Average sizes satisfy most people.

The Data

Preferred length: 5–6 inches insertable (most satisfaction)

Preferred diameter: 1.2–1.5 inches

Most people prefer: Average sizes, not extreme sizes

Girth vs Length

Girth matters for sensation (stretch, stretch, tightness).

Length barely matters beyond 5–6 inches (most sensation is front 2–3 inches).

Vaginal Depth

• Relaxed: 7–8 cm
• Aroused: 10–12 cm

Extra length beyond 6 inches provides no additional sensation.

Verdict

Size matters, but not the way pop culture suggests.

Average sizes (5–6" length, 1.2–1.5" diameter) satisfy most people.

Girth matters more than length.

Bigger ≠ better.

See also: the dildo sizing primer, the preference data on size, the average size, explained with data, and data from 900+ products on dildo size.