What’s the Proper Way to Measure Your Penis?

Proper Way to Measure Penis
Medically approved by
Dr Earim Chaudry
Last updated
30th July 2020

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There’s a right way and a wrong way to measure your penis.
Learning how to measure your penis (length, width and girth) is more important than you might think.
It’s not just about bragging rights — it’s also important to your sexual health.
Knowing the size of your penis means you can buy the correct size of condom, meaning you’re less likely to feel any discomfort if it’s too tight or run the risk of the condom tearing if it’s too loose. You need to measure along the top, from the tip to the pubic bone. 

At some point in your life, you’ve almost certainly grabbed a ruler or a tape measure and measured your penis. It’s something of a rite of passage for most men. Or, at the very least, a way to kill some time on a rainy Sunday afternoon. 

But here’s a question: Did you do it correctly?

Believe it or not, there is in fact a right way and a wrong way to measure your penis! And knowing how to do it right can be crucial to your sexual health.

Why Does It Matter?

It matters because if you purchase condoms believing your penis to be one size when it’s actually another, you could encounter one of two scenarios:

  1. The condom is too tight; so much so, in fact, that you remove it in the throes of passion.
  1. The condom is too loose, leading to it tearing or falling off prematurely. 

Both situations introduce the risk of unprotected sex, and you don’t need us to go into detail as to why that might be a bad thing

How to Measure Penis Length

Forget any old wives tales about correlating penis size from the distance between your thumb and index finger, or your shoe size, or your height, race, or the deepness of your voice. These have no basis in science. The only way to gauge the size of your penis is to measure it while it’s erect. 

Even then, penis size can vary slightly from one day to the next due to fatigue, stress, and level of arousal, so you may want to take several measurements to find an average for a more accurate picture. 

So, here’s how to correctly measure your penis:

  • Using a ruler or tape measure, start at the tip of the head of your penis.
  • Measure in a straight line along the top from the tip to the pubic bone.
  • To get an accurate measurement, make sure to push past any pubic hair or excess fat. Stop measuring at the pubic bone.
  • Note your measurement. That’s your actual penis length! 

Why Is This the “Right” Way to Measure Your Penis?

The method described above is precisely how medical researchers measure penis length. 

And it’s the “right” way because it has a clear stopping point (your pubic bone) and is therefore not open to interpretation. If you were to measure the underside of the penis instead of the top, results could be slanted or purposefully misrepresented by measuring past the testicles.

How to Measure the Girth of Your Penis 

While you’re at it, you can also measure the girth of your penis. To do this, simply:

  • Wrap a flexible tape measure around the middle of the shaft of your penis.
  • Note the measurement where the tape meets.

The average erect penis girth is 4.59 inches (3.66 inches when flaccid).

How to Measure Penis Width

Curiously, some condom manufacturers size their products according to the width or diameter of the penis. Thankfully, this is a relatively easy measurement to take. Once you have the girth, following the instructions above, simply divide by 3.14.

So, How Do You Measure Up?

From Alfred Kinsey’s pioneering research to the recent (and by far the largest) study of penis size, the average reported penis size has continually changed over the years. 

The results of the Kinsey study (where an average size was reported as 6.21 inches) pervaded popular culture for many years. This has led to both men and women overestimating the average penis size — women add over half a centimetre to the real average, while men believe it’s a full centimetre more than it actually is.

The main issue with the Kinsey study, and the many like it that followed, was that he asked only a small demographic of men (healthy college-aged individuals) to self-report their penis size. Not the most scientifically accurate approach to the task at hand! 

Which brings us to that recent study, which took measurements of over 15,000 men and found: 

  • The average length when erect was 5.16 inches (13.1cm).
  • The average girth at the widest part, meanwhile, was 4.59 inches (11.65cm).

The men were also broken down into percentiles, illustrating what percentage of men had a size over a particular measurement. Those with an erect penis measuring 6 inches (15.24cm) were in the 90th percentile, meaning only 10% of men had a larger penis. On the other hand, only 10% of men had a penis smaller than 4.33 inches (11cm).

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Using Your Penis Size to Choose a Condom

If you’re truly committed to precision, you’ll have taken a few measurements over the course of a few days and at different times to arrive at an accurate figure. Armed with this information, you should be able to select the right size of condom. 

Measuring in at or around the average size should mean a standard-sized condom will fit you without any discomfort or risk of falling off. If you’re larger than average, try a “large” and move up sizes from there if necessary. If you’re smaller than average, try one labelled “snug” or “close fit”.

In Summary

Although you may not have considered it, discovering how to accurately measure your penis is ultimately vital to your sexual health. Choosing the right condom is crucial to a safe and pleasurable sexual experience for all involved. 

And if measuring your penis brings a confidence boost and a spring in your step, then that’s an added bonus! 


  1. NHS – When sex goes wrong: https://www.nhs.uk/live-well/sexual-health/when-sex-goes-wrong/

  2. J ShahN Christopher (2002). Can shoe size predict penile length?: https://www.ncbi.nlm.nih.gov/pubmed/12230622

  3. Theodore M. Brown and Elizabeth Fee (2003). Alfred C. Kinsey: A Pioneer Of Sex Research: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1447862/

  4. David Veale, Sarah Miles, Sally Bramley, Gordon Muir, John Hodsoll (2014). Am I normal? A systematic review and construction of nomograms for flaccid and erect penis length and circumference in up to 15 521 men: https://onlinelibrary.wiley.com/doi/full/10.1111/bju.13010
  5. Kevin O’Keefe – The Average American: The Extraordinary Search for the Nation’s Most Ordinary Citizen: https://books.google.co.uk/books?id=EqhTDwAAQBAJ&pg=PT576&lpg=PT576&dq=kinsey+6.21+inches&source=bl&ots=HcVQxFG6XH&sig=ACfU3U3JnqAEvLL8U7KibN_6wnD3AADuqQ&hl=en&sa=X&ved=2ahUKEwijmc3TmsXoAhXOTcAKHUCoApsQ6AEwAHoECAkQAQ#v=onepage&q=kinsey%206.21%20inches&f=false

While we've ensured that everything you read on the Health Centre is medically reviewed and approved, information presented here is not intended to be a substitute for professional medical advice, diagnosis, or treatment. It should never be relied upon for specific medical advice. If you have any questions or concerns, please talk to your doctor.

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