How to Measure Your Penis Length and Girth

Find the best condom fit and get facts about penis size

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Learning how to measure your penis correctly helps ensure that you buy condoms that are properly sized and fit snugly. This not only involves measuring the length of your penis from the tip of the head to the pubic bone but also the width and girth (circumference) where the penis is widest. You need to do so with a ruler or measuring tape while you have an erection (stiff penis).

If you don't measure your penis correctly and an external (male) condom⁠ is too loose, it can fall off in the middle of sex and you may not even notice. If the condom is too tight, it may not only be uncomfortable but may actually break or burst.

This article outlines how to measure penis size correctly. It also explains how to use these measurements to choose the right condom size for you.

How to Measure a Penis

Verywell / JR Bee

How to Measure Penis Length

Here is how to measure penis length correctly:

  1. Position a ruler or measuring tape at the base of your erect penis where it attaches to your body.
  2. Press into your pubic bone as far as you can, until you contact the bone. This is especially important if there’s a lot of belly fat.
  3. Measure from the base of your penis to the end of its tip.

When measuring a penis, many people only think of the length of the penis, even though the girth is arguably more important with respect to comfort and fit. With that said, the erect penis length factors into how condoms in the United States are categorized and sold, with sizes ranging from "snug" and "regular/standard" to "large" and "extra-large."

What Is the Average Penis Length?

According to a 2015 review published in the British Journal of Urology International, the average erect penis size is smaller than some people think: 13.12 centimeters or roughly 5-1/5 inches. By contrast, the average flaccid (soft) penis length is 9.16 centimeters when unstretched, or just over 3-1/2 inches.

In the United States, condom length is categorized by inches as follows:

  • Snug condoms have a length of 7 inches to 7.8 inches.
  • Regular/standard condoms have a length of 7.25 inches to 7.8 inches.
  • Large condoms have a length of 7.25 inches to 8.1 inches.
  • Extra-large condoms have a length of 7.25 inches to 8.7 inches.

Condom size is particularly important if you have a penis longer than 8 inches. In such cases, you would need to get a condom such as Durex XXL Extra Long Extra Wide. If you don’t, it may leave part of the penis exposed to sexually transmitted infections (STIs) like herpes that can be passed through skin-to-skin contact.

You may also end up overstretching the condom and flattening the reservoir tip at the end meant to collect semen. This can cause the semen to seep out the sides.

How to Measure Penis Girth

Here is how to measure penis girth correctly:

  1. Use a soft measuring tape or a piece of string. If you choose the latter, make sure it doesn’t have any stretch. Using a length of yarn, for example, could result in measurement errors.
  2. Gently wrap the tape or string one time around the thickest part of the shaft of the erect penis.
  3. Note where the ends of the tape meet; that’s the number you’re looking for. If you’re using a string, mark where the end of the string meets the rest of it. Then, straighten out the string and use a ruler to measure the distance from the mark to the end. 

What Is the Average Penis Girth?

According to the same study in the British Journal of Urology International, the average erect penis girth is 11.66 centimeters or just over 4-1/2 inches. The average flaccid girth is 9.31 centimeters or around 3-1/3 inches.

Getting an accurate measurement of the penis girth is important as U.S. manufacturers will also categorize their condom sizes based on the circumference of your penis by inches as follows:

  • Snug condoms have a girth of less than 4.7 inches.
  • Regular/standard condoms have a girth of 4.7 to 5.1 inches.
  • Large condoms have a girth of 5.1 to 6 inches.
  • Extra-large condoms have a girth of over 6 inches.

The girth is especially important if you use condoms made of polyisoprene which is not as stretchy as latex and requires a more accurate fit. The same applies to extra-thin condoms that are more prone to bursting if the condom is too tight.

How to Choose the Correct Condom

Verywell / Alex Dos Diaz

How to Measure Penis Width

Some condoms are sized according to width or diameter. You can find this measurement the same way you would find the diameter of a circle. First, find the girth using the method described above. Then, simply divide that number by 3.14.

So, if your penis circumference is 7 inches, your penis width would be 2.23 inches (7 inches ÷ 3.14 = 2.23 inches).

Measure More Than Once

Penis size can vary due to stress, fatigue, frequency of sexual activity, and level of arousal. So you may want to do several measurements at different times throughout the day over several days.

Using Your Penis Size to Choose a Condom

Once you are confident that you've measured your penis size accurately, you should be able to determine what size condom you need.

If your penis is of average size, a standard-size condom should provide you with an accurate fit. A larger-than-average penis may need a condom labeled “large,” whereas a penis that is smaller may need a condom labeled “snug.”

Remember, when it comes to condoms, size matters. The better the fit, the better it will protect you against unwanted pregnancies and sexually transmitted infections.


To get the right condom fit, it is important to know how to measure your penis length, width, and girth. Some people use a ruler or measuring tape, while others use a string. Just make sure that whatever you use does not stretch as this can cause inaccurate measurements.

Once you have established the size of your penis while erect, you can use this information to find a condom that fits you properly.

1 Source
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Veale D, Miles S, Bramley S, Muir G, Hodsoll J. Am I normal? A systematic review and construction of nomograms for flaccid and erect penis length and circumference in up to 15,521 men. BJU Int. 2015;115(6):978-86. doi:10.1111/bju.13010

By Dawn Stacey, PhD, LMHC
Dawn Stacey, PhD, LMHC, is a published author, college professor, and mental health consultant with over 15 years of counseling experience.