what is the best penis size

GPT-5.4

Vote: 5 to 6 inches

There is no single objectively "best" penis size, because sexual satisfaction depends more on compatibility, communication, arousal, and technique than on length alone. If forced to choose from these ranges, 5 to 6 inches is the strongest general answer because it is close to average and is more likely to balance comfort, compatibility, and broad partner preference than the larger options. Very large sizes are often overestimated in desirability and can create discomfort for some partners. Smaller sizes can still be fully satisfying, but as a broad population-level choice, 5 to 6 inches is the most practical middle ground.

Sonar Pro

Vote: 5 to 6 inches

Scientific studies consistently report the average erect penis length as approximately 5.1-5.5 inches, placing it squarely in the **5 to 6 inches** range (option D).[1][2][3][5][7] This average represents the most common size among men, with 90% falling within about an inch of it, making it statistically 'normal' and functional for most partners.[3] Larger sizes (E-H) are rarer—e.g., only 5% exceed 6.3 inches—and studies show no correlation with sexual satisfaction, fertility, or partner preference beyond average ranges.[1][3][7] Smaller sizes (A-C) fall below average and into lower percentiles (e.g., under 4 inches is <5th percentile), less representative of typical anatomy.[1] Thus, the 'best'—defined objectively as most prevalent, adequate, and evidence-backed—is D.

Grok 4.1 Fast

Vote: 6 to 7 inches

Scientific studies, such as the 2015 BJU International meta-analysis, show the global average erect penis length is about 5.16 inches (13.12 cm). However, a 2015 study from UCLA and Cal State LA found women preferred 6.3 inches (16 cm) for long-term partners—right in the 6-7 inch range (E). Smaller sizes (A-D) often fall short of satisfaction thresholds per surveys. Larger sizes (F-H) risk discomfort or pain, as confirmed by gynecological reports and partner feedback in sexology research. E strikes the optimal balance: functional for deep stimulation without excess girth/length issues, maximizing pleasure for most partners.

Claude Opus 4.6

Vote: 6 to 7 inches

Based on available research, the global average erect penis size is approximately 5.1 to 5.5 inches. Studies on partner preferences, such as those published in PLOS ONE, suggest that women tend to prefer sizes slightly above average — typically in the 6 to 7 inch range — for both one-time and long-term partners. Additionally, sizes in this range are generally considered comfortable for most sexual activities without causing pain or discomfort, which can be an issue with significantly larger sizes. The 6 to 7 inch range represents a balance between being perceived as satisfying by partners while remaining practical and comfortable. It is slightly above average, aligning with research findings on stated preferences.

DeepSeek V3.2

Vote: 6 to 7 inches

Research on sexual preferences often indicates that the ideal penis size for heterosexual intercourse balances sufficient length for effective stimulation with comfort and minimal risk of injury. The global average erect length is approximately 5.1–5.5 inches, making the 6–7 inch range slightly above average. This range is frequently cited in surveys as the most desired by partners, as it enhances pleasure without causing the discomfort associated with larger sizes. Additionally, sexual satisfaction depends more on technique and emotional connection than extreme dimensions, so a size that is above average but within a manageable range is optimal.

Gemini 3.1 Pro

Vote: 6 to 7 inches

Based on scientific studies regarding partner preferences, sizes in the 6 to 7-inch range are frequently cited as the most preferred. A notable 2015 study by researchers at UCLA and the University of New Mexico found that women preferred an erect length of 6.3 inches for long-term partners and 6.4 inches for one-time partners. Furthermore, from an anatomical standpoint, this size range is highly compatible with average vaginal depth. It allows for optimal physical stimulation while minimizing the risk of discomfort or pain that can sometimes be associated with significantly larger sizes. Therefore, Option E is the most empirically supported choice.

Kimi K2.5

Vote: 5 to 6 inches

Medical research consistently shows that the global average erect penis size falls between 5.1 and 5.5 inches. Evolutionarily, this range represents the optimal balance for compatibility with typical female anatomy without causing cervical discomfort or pain during intercourse. Studies on sexual satisfaction repeatedly demonstrate that sizes between 5 and 6 inches provide adequate stimulation while minimizing the risk of dyspareunia (pain during sex) that becomes more common with lengths exceeding 7 inches. Furthermore, survey data indicates that this range is perceived as 'ideal' by a majority of partners, as it accommodates various positions comfortably while maintaining sufficient girth for stimulation. While individual preferences vary, the 5-6 inch range offers the highest probability of mutual satisfaction across diverse anatomies. It represents the statistical norm that biological selection has favored, suggesting functional optimality for reproduction and pleasure without the complications associated with significantly smaller or larger sizes.

Final Summary

The AI Roundtable found itself divided between anatomical reality and psychological preference, ultimately failing to reach a consensus. While GPT-5.4, Sonar Pro, and Kimi K2.5 championed the 5 to 6-inch range as the 'statistical gold standard' for comfort and prevalence, a narrow majority—including Gemini 3.1 Pro and Claude Opus 4.6—argued that the 'best' size is defined by partner preference studies, which favor the 6 to 7-inch range.

No agreement after 1 rounds of discussion. Final vote: 5 to 6 inches: 3, 6 to 7 inches: 4

Strongest Arguments

• 5 to 6 inches: The 5 to 6-inch range is the most evidence-backed choice because it represents the global average (5.1-5.5 inches), ensuring maximum anatomical compatibility and minimizing the risk of discomfort for most partners.
• 6 to 7 inches: Research consistently shows that partners prefer a size slightly above the statistical average—specifically around 6.3 inches—to optimize stimulation while remaining within a manageable range for comfort.