How to measure your penis size properly

Learning how to measure penis size doesn’t have to be complicated. First things first: ditch the ruler. To get the most accurate measurement, you’ll need a flexible measuring tape (or a piece of string) and a fully erect penis. Different methods are used to measure length and girth, and small mistakes can throw off your numbers. 

Whether you’re shopping for condoms or just curious (who isn’t?), this guide will show you how to measure your penis length and girth accurately.  

When you measure your penis size, a soft measuring tape is better than a hard ruler for multiple reasons. First, many men have a curved penis, and only a measuring tape can be accurately placed along the curve of your penis. A curved penis might appear shorter with a rigid measurement device. 

Secondly, if you want to measure the girth of your penis — aka how thick it is — a measuring tape, or any other type of flexible tape measure, is needed anyway.

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The proper way to measure the length of your penis is from the top side rather than the bottom side. That’s because measuring the top of the penis has a clear stopping point — the pubic bone — which makes it a more reliable measurement than the bottom of your penis.

When you measure the underside of the penis, you can skew results by measuring into the balls area. Side note: It doesn't make much difference if you are circumcised or uncircumcised. The foreskin doesn't add length to the penis when erect.

Before you can measure penis length, you’ll need to get an erection. Whether you’re a grower or a shower, it’s totally normal for your penis to change size when erect, which is why erect measurements are considered the most accurate.  

Here’s how to correctly measure your penis length:

1. Start at the top side of your penis. Measure along the side facing upward towards you when you look down. 

2. Place the measuring tape at the base of the penis. Press the tape against the pubic bone where the penis meets the body. Be sure to push past any excess fat or pubic hair so that the tape is right up against the bone. 

3. Measure to the tip. Measure in a straight line from the pubic bone to the tip of the penis. 

4. Record your measurement. Write down the length in inches or centimeters. Research suggests the average length of an erect penis is 5.1–5.5 inches, but your measurement may vary.

How to measure the girth of your penis

Here’s how to properly measure the girth of your penis: 

1. Wrap the measuring tape around the thickest part of your penis. This is usually around the middle of the shaft. 

2. Make sure the tape fits snugly around the skin without squeezing too tightly. If you don’t have a measuring tape, feel free to use a string, which you can measure against a ruler later.

3. Measure the circumference. The number where the tape overlaps is your pernis girth (circumference). Record the measurement in inches or centimeters.  Research shows the average erect penis girth is 4.5–4.6 inches, though, again, your results may vary.

You should measure your penis when erect. Generally, erect measurements are considered more accurate and consistent. 

Research suggests that stretched flaccid measurements can underestimate the erect size by around 20%. This is partly because the amount of stretch can vary person to person. 

Regardless of how you measure, your penis is probably — statistically speaking — large enough. And whether you have an above-average or a penis that’s on the smaller end, it’s still possible to have a satisfying sex life and feel confident in your body.

Still concerned? Speak with your urologist or another healthcare provider for medical advice if you’re worried about your penis size or if you’re experiencing conditions like erectile dysfunction (ED) or premature ejaculation (PE).  

When measuring your penis, avoid the following pitfalls, which could lead to inaccurate data:

• Measuring with a ruler. Not only is it difficult to measure a curved penis with a rigid ruler, but you also can’t measure your penis girth with one. Instead, use a flexible measuring tape or a piece of string (which you can then measure against a ruler).

• Measuring while partially erect. Measurements taken while your penis is semi-erect or flaccid can vary significantly. Be sure to measure your penis when fully erect for the most accurate result.

• Not pressing to the pubic bone. Press the end of the measuring tape firmly against the pubic bone at the base of your penis. Excess fat or pubic hair can throw off your results.

• Measuring from the bottom. Measuring from the underside of your penis can lead to incorrect results, because you may include part of the scrotum in your measurement.

• Stretching the penis. Some studies use a stretched flaccid measurement to estimate erect size, but research suggests this method can be inconsistent because the amount of stretch varies from person to person.

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Learning how to measure your penis isn’t about comparing yourself to others. Knowing your measurements can be useful when you’re choosing the right condom size and can help you get a better understanding of your body. 

Here’s what to remember:

• Measure while fully erect for the most accurate results. It’s no surprise that your penis increases in size when you get an erection. Research also suggests erect measurements are more consistent than flaccid or stretched measurements.

• Use a flexible measuring tape instead of a ruler. A flexible measuring tape works best when calculating your girth. You also can’t properly measure a curved penis with a rigid ruler.

• Penis size varies from person to person. Research suggests the average erect penis length is around 5.1–5.5 inches, with an average erect girth of 4.5–4.6 inches. Keep in mind that penis size varies widely, and measurements outside these averages are often still normal.”

• A smaller-than-average penis shouldn’t get in the way of sexual satisfaction or confidence. Penis size varies widely, and people of all sizes can still have satisfying sex lives and feel confident in their bodies. If you’re concerned about sexual performance, talk with a healthcare provider.”