Soccer cleats do not come in widths, which can make it difficult to obtain a good fit. Since many medium width cleats will run either wide or narrow, you can use a side-by-side comparison to identify volume differences between different pairs of shoes.
The two pairs of cleats below illustrate a narrow lasted cleat on the left, Adidas Predator Absolion TRX , and a wide lasted cleat, Nike Mecurial Victory II, on the right. The differences in width are highlighted.
Comparing the uppers, notice how the throatline (opening) of the Nike is so much wider than the Adidas. Also notice the difference in toebox shape and width. The Adidas is more tapered around the toes and the Nike is more rounded, accommodating a wider forefoot.
In evaluating the lower, you can see how much wider the forefoot and waist are in the Nike than the Adidas as well. If you have been having difficulty finding the perfect fit, using this method should help. These principles also apply to other shoes (tennis, basketball, football, etc.) that only come in medium widths.
Dr. Jenny Sanders Shoe Blog 
Having a background fitting shoes and arch supports,I could never understand why the athletic shoes for kids and adults who play
soccer and various other sports,that they do not come in wide widths
accommodating the already over work load of the foot.These shoes do
not allow the foot ample circulation and no protection,crippling those
who love the sports they play.
Sizing cleats is so important. I make sure my daughters cleats always fit right before playing sports. When I was younger I had the hand me downs that were too big and I use to get black in-grown toenails. Always hurt so bad and made me retire sports season early.
The modern “slipper” leather can stretch, so the width of the upper may be accommodating, except for the fact that there may develop a gap between the upper and the insole…. sufficient, for example, to produce a blood blister for a Man Utd Welsh International whose contract switched him from Adidas to Puma – painfully as it turned out.
It is also fortunate that there is no longer a receptacle on the insole for the screw in cleat/stud.
Nike’s MV cleats are famous for narrow, but this Adidas is narrower…sigh…
I tried these cleats in shops:
Puma powercat 1.10=narrow
Nike MV II=narrow
Adidas F50=narrow
Lotto Zhero Gravity=narrow
Mizuno Ignitus II=just ok
Nike T90=just ok
sigh…:(