There are lots of ways to declare your restoration a success, but perhaps the most dependable way to know you’re making progress is to measure Forced Erect Coverage. Here is a mathematical approach which is a TLC Tugger innovation.
Forced Erect Coverage (FEC): An indication of how much slack skin is present on the penis. It’s just the percentage of your glans length that you can force skin over while you’re erect. For example, if you can cover half the glans that’s 50% FEC.
To measure FEC, get fully erect and force the shaft skin away from your body, toward your glans. Try to FORCE the skin over the corona and glans (but not to cause pain). Measure the length of the part of the glans that is still showing on top (from the tip back to where the skin rolls under). Then let the skin roll off the glans and measure the length of the whole glans on top while still fully erect.
FEC = [1 – (glans showing / whole glans)]
The number is a percentage. For example, with 1″ of glans showing, and 1.5″ for the length of the whole glans, FEC = [1 – (1 / 1.5)] = (1 – 2/3) = 1/3 = 33.3%
If you can’t force the roll of skin to reach the glans then the FEC result will be negative. For example, with skin forced forward but falling 0.1″ short of reaching the glans, and 1.5″ for the length of the whole glans, the glans showing is 1.5 + .1 = 1.6 and FEC = [1 – (1.6 / 1.5)] = 1 – (16/15) = -1/15 = -6.7%
Once it’s possible to cover more than the whole glans, the Forced Erect Coverage number includes the skin-tube reach distance past the glans as “negative” glans showing. You may need a pen or other blunt slender tool to sound the distance from the end of the bunched-up skin to the tip of the glans. For example, with skin forced 0.5″ past the tip of the glans, and 1.5″ for the length of the whole glans, FEC = [1 – (-0.5 / 1.5)] = 1 – (-1/3) = 1+1/3 = 133.3%
A typical foreskin restorer can add at least 1 mm per month to the amount of the glans that can be forcefully covered with skin while erect. Lots of guys progress faster. Our 2010 controlled trial participants averaged 3mm of improvement per month while tugging an average of 11 hours per day. If you’re just starting out, take your before pictures and measure FEC, but wait until you have been using a consistent regimen for a week before taking your official baseline FEC measurement which you will compare to your monthly readings.
So let’s do some real-world cases:
Here in the first picture the glans length is measured at 39mm. With the skin forced up while erect in the second picture you can see 14mm of glans showing.
So the forced erect coverage is: FEC = (1 – 14/39) = 64.1%
In another example, say a different man’s skin can instead be forced PAST the tip. In this picture see how a blunt tool can be used to sound the depth within the skin tube, prodding until the tip of the glans is touched (of course be careful nothing enters the urethra).
The tool is withdrawn and the distance from the observed coverage point to the end is measured at 24mm. So the FEC is: FEC = (1 – (-24/39)) = 161.5%.
Note that in the above photos, the hand forcing the skin is positioned to allow an example measurement to be photographed. In practice that hand might be gripping closer to the end of the skin tube and stressing the skin noticeably.
FEC is a useful calculation when comparing your coverage improvements to those of someone whose penis is a different size, or if you don’t care to share your penis size when comparing progress. But if you only want to know that you yourself are making consistent progress, it’s easier to just log Forced Skin-tube Reach monthly. That is just the “glans showing” attribute in the above illustrations. How much of your glans is sticking out (still uncovered) when you force the skin forward while erect?
On the matter of accuracy and consistency of measurements, the tricky parts about FEC are being FULLY erect and forcing skin AS FAR AS it will go without causing pain. The pain thing is for each individual to gauge. As for full erection, if you repeat the measurement a few times in the span of a couple minutes, the largest glans length you get would correspond to the fullest erection. The largest “glans showing” number that you get while rolling skin up would also correspond to the fullest erection (assuming you’re forcing your skin equally as hard each time) so use the largest numbers you would record on a certain day in all cases.
To re-iterate, you should FORCE the skin over the glans with no regard at all to where the skin came from or how hairy it is, because this technique of tugging just short of the point of causing pain is the way to get a reproducible measurement.