Drag the red handle at the tip to set length and the yellow tape to set girth, or type your numbers. Everything below updates as you go: where you rank, how you compare with any size you choose, what partners say they want, what to expect in bed and which condoms fit.
Use erect measurements. Nothing you enter is saved or sent anywhere.
Units
Rank against
Length
Girth
Diameter
Volume vs average
Along the top, from the pubic bone to the tip.
The distance around the middle of the shaft.
Drawn to scale. Each grid square is 1 cm.
Where you fit
If 100 men lined up by length
See the difference
Pick what to compare yourself with. Everything is drawn to the same scale.
Compare with
Girth, seen end on
The women's picks come from a study in which 75 women chose from 33 3D-printed models (Prause et al., 2015).
What to expect in bed
Every size comes with real advantages. Whatever yours is, the things partners value most, like attentiveness, communication and foreplay, are entirely in your control.
Condoms that fit
Worth knowing
The famous 6-inch average comes from men measuring themselves. Measured by health professionals with the ruler pressed to the bone, the erect average is about 5.5 inches (13.9 cm) long and 4.5 inches (11.5 cm) around.
Only about 5% of men are longer than 6.6 inches (16.7 cm) erect, and about 5% are shorter than 4.4 inches (11.1 cm).
85% of women say they're satisfied with their partner's size. Only 55% of men say they're satisfied with their own.
When women chose from 3D-printed models, they picked about 6.3 by 4.8 inches for a long-term partner and slightly bigger for a one-night stand.
Girth tends to matter more to partners than length.
Flaccid size is a poor guide to erect size. Some men gain a lot of length when erect and some gain very little.
Shoe size doesn't predict penis size, and height only weakly does.
Enlargement pills don't work. Many "male enhancement" products have been found to contain hidden prescription drugs.
How to measure
Measure when fully erect, standing up.
For length, lay a rigid ruler along the top. Press it gently into the fat pad until it touches the pubic bone, then read the number at the tip.
For girth, wrap a soft tape or a piece of string around the middle of the shaft, then measure the string.
Measure on a few different days and use the average.
Measuring along the underside, or measuring girth at the base, gives bigger numbers than the studies use, so your ranking would be off.
Worried about your size? Most men who seek help for it turn out to be in the normal range. If it's affecting your confidence or your sex life, a GP or a sex therapist can help.