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Let's talk about measuring penises. Specifically, your penis.

While the commmon refrain is "size doesn't matter", in reality it does matter in some ways. In particular, accurate measurements are vital for condom sizing. And while it's not "important", if you want to know where you fit on the scale of penis size then you first need to know how big your penis is — and to measure it the same way as the researchers did.

Thankfully, measuring your penis is a relatively straightforward affair. There are two measurements that are important: length and girth (circumference). It's best to have a tailors tape or cloth tape measure handy for these steps.

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How to measure the length of your penis:

  1. Stand up. Have your rule nearby.
  2. Get as fully erect as you can.
  3. Place the rule on top of your penis.
  4. Press the end of the rule into the pubic fat pad at the base of your penis until it stops at your pubic bone.
  5. Straighten any curvature in your penis as best as you can.
  6. Note the measurement at the far end of the rule; that's your length.

Why is it done this way? This is how penis length is scientifically measured, and the only valid way to measure for comparison to penis size charts and statistical tools like CalcSD. Measuring along the top and pressed to the pubic bone provides a common point of reference for comparison and controls for factors that only affect the visible size of the penis but not the actual length, like excess body fat. The pubic bone directly above the penis is the most forward-projecting part of the bone and a solid depth limiter for many sex positions. Measuring to the side or from underneath is not valid, no matter how much more length you feel you should be allowed to claim.

Pressing to the pubic bone is known as the "bone-pressed erect length" (BPEL, or just BP). Fat is highly compressible, so unless you're obese you'll still be able to use most of your penis during intercourse. Measuring just the exposed shaft is called the "non-bone-pressed erect length".

Standing, like bone-pressing along the top, sets a common standard. Different postures can positively and negatively affect the actual and apparent size of your erection by changing the localized blood pressure and hip position. Standing normalizes those factors across the board.

Don't have a ruler? Go buy one. They're cheap and super useful all around the house. A flexible fabric tailor's tape is also a great and cheap tool to have on hand.

If your penis is so curved that you are unable to straighten it, don't just measure in a straight line from base to tip, and don't just drape a tape measure over your curve. This exercise isn't about claiming the biggest number possible. Measure along the outside of your curve and then the inside, making sure to start both measurements at the same point as you would bone-pressed. Then average those two numbers (add them, then divide by two) to get your mid-line length that should be very close to what you'd get straightened.

How to measure the girth of your penis:

  1. Stand up.
  2. Get as fully erect as you can. Have a tailor's tape measure or a narrow strip of paper nearby.
  3. Wrap the tape around the thickest part of your shaft. Tighten it to where it is snug enough not to freely move, but not so tight that it is compressing your penis.
  4. Note where the measure overlaps. That's your girth.

Don't use a string, rubber band, or other elastic material for your measurement; the stretch may underestimate your girth. Also don't use anything thick like a charging cord, even if flexible, as it will skew your number when straightened back out. Tailor's tape or a paper strip, that's it.

Only measure girth on the exposed shaft. While your penis may be thickest under the pubic fat pad, there's no way to reliably measure that. In addition, girth measurement is most useful for condom sizing, and you can't unroll a condom into the fat pad anyway.

Take care to ensure you're not wrapping up any scrotum skin under the measuring device. And even if you have a large glans (cock head), girth measurements should be done on only the shaft. If you have a glans that is significantly thicker than your shaft you can always measure it separately.

Variations in size

It is totally normal to vary in size from erection to erection. Several factors contribute to the strength and size of any one boner. The biggest input is your level of arousal: you'll have a larger erection with a partner than when solo, and you'll be at your largest when you're close to orgasm. Other factors like how recently you've exercises, hydration, rest levels, cardio health, and body positioning also have an impact on your erection strength.

It's not a bad idea to measure a few times over the course of a few weeks to get an idea of your own personal range. Don't get upset if you're not always hitting your peak potential; there's not always a rhyme or reason why our dicks do as they do.

Is it big? Small? Average?

The big question, and really the only reason that most guys measure, is to find out where they fit on the scale of penis size. You want to know if you've got a big one. It might seem like it's a simple answer of "X inches or longer is big", but the reality is a bit more complicated than that.

But when you get down to it, the average penis is roughly 5.5 inches long and 4.5 inches around, and the vast majority of penises land within half an inch on either size of those measurements. Want to know more? Hit the links below for everything you need to know about penis size!

Penis Size Chart

Grower or Shower

Penis Size Visualizer