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So you hear a lot about big dicks, but what size makes a dick big? And for that matter, what would an average-sized penis measure? And what's small?

Erect Length

Penis size is something that science has studied extensively, and study after study has come back with an average number for erect penis length somewhere between 5 and 6 inches length. When you pool the data from dozens these studies together, as the folks behind CalcSD did you get a global erect average of 5.5 inches / 14.0cm long.

Surprised? Well, that's the science, and they're not interested in lying to you. If that conflicts with your expectations, you need to remember that men have a tendency to exaggerate their size and that exaggeration rubs off on women too. Science cares about the truth, not feelings.

With our average number set, we can look at the standard deviation (a measure of how much variation there is in the dataset) and extrapolate out just how rare a big penis actually is. Half a standard deviation above and below the median gets us a central "average" range, which covers the middle 40% of dicks: 13.2-15.0 cm / 5.2-5.9 inches.

From there, we can extrapolate out, stepping out by standard deviations to go up and down the range of penis lengths.

Erect penis length chart

classification cm inches percentile vs. average
micropenis <8.1 cm cm <3.2 inches <0.02 >42% shorter
very small 8.1-9.8 cm 3.2-3.9 inches 0.02%-0.6% 42-29% shorter
small 9.8-11.5 cm 3.9-4.5 inches 0.6-7% 29-18% shorter
below average 11.5-13.2 cm 4.5-5.2 inches 7-30% 18-5% shorter
average 13.2-15.0 cm 5.2-5.9 inches 30-70% 5% shorter – 5% longer
above average 15.0-16.7 cm 5.9-6.6 inches 70-93% 5-18% longer
big 16.7-18.4 cm 6.6-7.3 inches 93-99.4% 18-29% longer
huge 18.4-20.2 cm 7.3-7.9 inches 99.4-99.98% 29-42% longer
enormous 20.2-21.9 cm 7.9-8.6 inches 99.98-99.999% 42-56% longer
truly massive >21.9 cm >8.6 inches >99.999% >56% longer

Erect Girth

But.. let us not forget about girth. If anything, girth is the more impactful of dimensions, versus length. CalcSD's dataset points to the average penis measuring 11.5 cm / 4.5 inches in circumference at its thickest point, which gives us an average range of 10.8-12.1 cm / 4.3-4.8 inches covering the middle 40% of dicks.

Extrapolating out again from that point, we can define the range of girths.

Accurate girth data is especially important for proper condom sizing, as those are sized based on the dick's thickness, not length.

Erect penis girth chart

classification cm inches percentile vs. average
micropenis <7.1 cm <2.8 inches <0.02% >37% thinner
very small 7.1-8.3 cm 2.8-3.3 inches 0.02-0.6% 37-26% thinner
small 8.3-9.6 cm 3.3-3.8 inches 0.6-6% 26-16% thinner
below average 9.6-10.8 cm 3.8-4.3 inches 6-30% 16-6% thinner
average 10.8-12.1 cm 4.3-4.8 inches 30-70% 6% thinner – 6% thicker
above average 12.1-13.4 cm 4.8-5.3 inches 70-94% 6-16% thicker
big 13.4-14.6 cm 5.3-5.8 inches 94-99.4% 16-26% thicker
huge 14.6-15.9 cm 5.8-6.3 inches 99.4-99.98% 26-37% thicker
enormous 15.9-17.1 cm 6.3-6.8 inches 99.98-99.999% 37-51% thicker
truly massive >17.1 cm >6.8 inches >99.999% >51% thicker

Flaccid Size

So now you know how your hard-on fits into the grand scheme of penises, but what about when soft? While flaccid measurements vary all over the place all day long, we still know what our "typical" softie is like. But is it normal? And are you a grower or a shower?

Science has an answer there too: the average flaccid penis measures 9.0 cm / 3.5 inches long. The bell curve on penis size is even narrower on soft measurements, with a central standard deviation covering 60% of flaccid penises for an average range of 3.3-3.8 inches / 8.3-9.7 cm.

Flaccid penis length chart

classification cm inches percentile vs. average
tiny <4.1 cm <1.6 inches <0.03% >54% shorter
very small 4.1-5.5 cm 1.6-2.2 inches 0.03-0.7% 54-39% shorter
small 5.5-6.9 cm 2.2-2.7 inches 0.7-7% 39-23% shorter
below average 6.9-8.3 cm 2.7-3.3 inches 7-30% 23-8% shorter
average 8.3-9.7 cm 3.3-3.8 inches 30-70% 8% shorter – 8% longer
above average 9.7-11.1 cm 3.8-4.4 inches 70-93% 8-23% longer
big 11.1-12.5 cm 4.4-4.9 inches 93-99.2% 23-39% longer
huge 12.5-13.9 cm 4.9-5.5 inches 99.2-99.97% 39-54% longer
enormous 13.9-15.3 cm 5.5-6 inches 99.97-99.999% 54-70% longer
truly massive >15.3 cm >6 inches >99.999% >70% longer

Like soft length, science also has an answer for soft girth. It can be a little squishy to measure, but the same principles apply. With thousands of penis measurements to run numbers off of, we can confidently say that the average soft penis has a girth of 9.0 cm / 3.5 inches. There's typically not a lot of variation in flaccid circumference, so the average range of 8.5-9.4 cm / 3.3-3.7 inches covers the middle 60% of men.

Flaccid penis girth chart

classification cm inches percentile vs. average
tiny <5.6 cm <2.2 inches <0.02% >37% thinner
very small 5.6-6.6 cm 2.2-2.6 inches 0.02-0.6% 37-27% thinner
small 6.6-7.5 cm 2.6-3.0 inches 0.6-7% 27-16% thinner
below average 7.5-8.5 cm 3.0-3.3 inches 7-30% 16-5% thinner
average 8.5-9.4 cm 3.3-3.7 inches 30-70% 5% thinner – 5% thicker
above average 9.4-10.4 cm 3.7-4.1 inches 70-93% 5-16% thicker
big 10.34-11.3 cm 4.1-4.5 inches 93-99.4% 16-27% thicker
huge 11.3-12.3 cm 4.5-4.8 inches 99.4-99.98% 27-37% thicker
enormous 12.3-13.2 cm 4.8-5.2 inches 99.98-99.999% 37-48% thicker
truly massive >13.2 cm >5.2 inches >99.999% >48% thicker

How to measure

Measuring your dick is straightforward, and yet full of complications. In the simplest form, to measure length you should you place a ruler on top of your erect penis, press into the pubic fat until it stops at the bone, and then note the measurement at the end. To measure girth, wrap a soft measuring tape or a strip of paper around the thickest part of your penis.

How to measure your penis