Penises come in all shapes and sizes, and they can vary considerably. While many men worry their penis is too small, research shows that most men's penises are normal and they needn't be concerned.
A 2014 study, which included 15,521 men from around the world, determined that:
The average flaccid penis was 9.16 cm, or 3.61 inches (in), long and 9.31 cm (3.66 in) in girth.
The average erect penis was 13.12 cm (5.16 in) long and 11.66 cm (4.59 cm) in girth.
The authors estimated that 5 percent of men have an erect penis longer than 16 cm.
In another 5 percent, the erect penis would be shorter than around 10 cm.
Lose weight: If you are overweight, those extra pounds can make your penis appear smaller. Losing weight can make your penis appear relatively larger. Regular exercise can make a big difference. Better physical conditioning may not only make you look better, but also can improve strength and endurance during sex.
Stay in shape: A muscular physique may add to this visual effect and make you feel more confident about the size of your penis.
Groom your pubic area: Shaving some of the hair around the penis could make the penis appear larger as well.