How To Measure Your Penis Correctly (Length And Girth)
Most men who think they are below average have measured themselves wrong. Measuring from the side, using a soft tape on the shaft, or measuring a partial erection can easily cost you half an inch to an inch. Here is how to measure the way clinical researchers do, so your numbers can be compared fairly to real averages.
What You Need
- A rigid ruler marked in inches or centimeters, for length. A flexible tape bends and gives inconsistent results.
- A soft tape measure, or a strip of paper or string you can mark and then lay against a ruler, for girth.
- A warm, private room and a few relaxed minutes. Cold and nerves make the penis smaller.
How To Measure Erect Length
- Get a full erection. A partial erection can be noticeably shorter.
- Stand up and hold the penis so it points straight out, parallel to the floor.
- Place the ruler on top of the penis, not on the side or underneath.
- Press the end of the ruler gently into the fat pad above the base until it touches the pubic bone.
- Read the length at the tip of the head. Do not include foreskin that extends past the tip.
This is called bone-pressed erect length, and it is the method used in most clinical studies, including the 2015 BJU International review by Veale and colleagues that set the clinical average at 5.2 inches (13.1 cm).
Bone-Pressed Vs Non-Bone-Pressed
Measuring from the skin surface without pressing into the fat pad gives non-bone-pressed length. The difference depends on how much fat sits over the pubic bone. In lean men it may be a fraction of an inch, while in heavier men it can be an inch or more. Always use bone-pressed length when comparing with clinical data.
How To Measure Girth
- With a full erection, wrap a soft tape measure around the middle of the shaft. Some men measure at the base and the thickest point too.
- Keep the tape snug but not tight.
- Read the circumference. If you use string or paper, mark where it overlaps, then measure that length on a ruler.
The clinical average erect girth is 4.6 inches (11.7 cm).
How To Measure Flaccid And Stretched Length
- Flaccid length: Measure along the top, from the pubic bone to the tip, while soft. This varies a lot with temperature and mood, so it is the least reliable measurement.
- Stretched length: Hold the head and gently pull the soft penis to its full length without causing discomfort, then measure along the top from the pubic bone. Doctors use stretched length because it closely approximates erect length and does not require an erection. The clinical average is 5.2 inches (13.2 cm).
Common Measuring Mistakes
- Measuring from the side or underneath. Inconsistent and not comparable to studies.
- Not pressing to the bone. Can cost an inch or more if you carry weight around the middle.
- Measuring a partial erection. Measure at your firmest.
- Measuring once. Erections vary day to day. Take three measurements on different days and use the average.
- Rounding up. Tempting, but it only makes the comparison less useful to you.
- Comparing with self-reported numbers. Online polls run high. Compare with clinical averages instead.
Penis Measurement Chart
| Measurement | How To Measure | Clinical Average |
|---|---|---|
| Erect length | Top side, pressed to pubic bone | 5.2″ (13.1 cm) |
| Erect girth | Around mid-shaft | 4.6″ (11.7 cm) |
| Stretched length | Soft, gently stretched, top side | 5.2″ (13.2 cm) |
| Flaccid length | Soft, top side | 3.6″ (9.2 cm) |
| Flaccid girth | Around mid-shaft, soft | 3.7″ (9.3 cm) |
What To Do With Your Numbers
Enter your erect length and girth into our Penis Size Visualizer to see your percentile against both clinical data and The Definitive Penis Size Survey, drawn to scale. Then put the ruler away. Measuring over and over tends to feed worry rather than settle it. If size worries are getting to you, read Am I Too Small?
Frequently Asked Questions
Should You Measure Penis Length From The Top Or Bottom?
From the top. Press the ruler gently into the fat pad until it touches the pubic bone and measure to the tip. This is the method used in clinical studies.
Do You Measure From The Base Or Pubic Bone?
From the pubic bone. Pressing past the fat pad gives bone-pressed length, which is consistent and comparable to clinical averages.
Where Do You Measure Girth?
Around the middle of the erect shaft. Some men also record the girth at the base and at the thickest point.
Is Stretched Length The Same As Erect Length?
Close. In clinical studies, the average stretched flaccid length was almost the same as the average erect length, which is why doctors often use it.
How Often Should I Measure?
Take three measurements on different days, average them, and then stop. Repeated measuring tends to increase anxiety.