What is considered the desired length for an Ivy League Haircut?

How short should the sides and back be (If I want to keep them a little longer) and how short should the top be? Also, does it take someone professional to cut this style?What is considered the desired length for an Ivy League Haircut?
It depends on the slope of the skull to the front hairline, but roughly an ivy league is, as noted in the Max Factor Standard Crew cut ad , around 1.5'; at the front hairline tapering to about 1/2'; to 3/4'; at the back of the crown. There are numerous names for this haircut. It is the original crew cut as worn by ivy league crew team members. It was also called a Princeton cut or just Princeton. Harvard Clip was another regional name. When crew cuts started getting shorter in the mid to late 1950's the name ivy league crew cut or standard crew cut came about to distinguish the crew cut that had the original longer length. Before the word crew cut, the style was known as a short pomp, or more specifically a round top short pomp. The other short pomp variant, the brush top short pomp became the flat top crew cut and later flat top. It was named a brush top short pomp because the top of the hair resembled the flat bristle surface of a brush.

http://f.imagehost.org/0796/shortpompdd6

The back and sides can be as short as one wishes. They are not critical since they grow out quickly. Consider that one and a half inches at the front hairline represents three months of growth at the average rate of growth of 1/8'; per week. Even very short sides cut at #1(1/8';) will be fairly standard sides cut at #2(2/8';) or #3(3/8';) in a week or two. Some guys purposely have the back and sides cut shorter than they like, to make the haircut look better for a longer period as it grows out. One has to think in terms of proportional changes in lengths on the back/sides versus the top with short styles. A way to roughly estimate lengths in a photo of an ivy league or any haircut is to measure the hair length in the photo and then measure the distance from the center of the front hairline to the tip of the chin and assume a fairly standard face length for an adult male face of 8';, then proportionally adjust the length of the hair in the photo. A lot of guys are surprised to see that the length at the short pomp front of some short styles is much longer than they would have imagined. And yes, it usually takes a skilled barber to do a good job of cutting an ivy league or crew cut, though there is no reason a skilled amateur cannot do a great job if he has cut ivy leagues and crew cuts before. I doubt the barber in the first linked photo below is a professional. Be sure to understand that with an ivy league or any crew cut, the top is graduated in length longer to the front hairline. The general idea is that the outline of the top hair should approach the horizontal when the hair is brushed back off the forehead and the head is viewed in side profile. When viewed from the front, the outline of the top hair can conform to varying degrees to the contour of the skull. Here are a few more photos of ivy league haircuts. Some old, some new, as it's a timeless style...

http://f.imagehost.org/0212/Crew_Cut_WW2

http://f.imagehost.org/0385/Jarrett_More

http://f.imagehost.org/0792/Jarrett_More

http://f.imagehost.org/0478/pearsontheod

http://i.imagehost.org/0085/jensen_ackle

http://f.imagehost.org/0994/jensen-ackle

http://i.imagehost.org/0791/ae218215599f

http://i.imagehost.org/0481/fsellssamuel

http://f.imagehost.org/0087/ilmatt07.jpg

I honestly recommend going for a regular taper cut first. Tapering up the back and sides is a huge change from your present length. If you do get an ivy league, get some krew comb(jar) or some other wax to groom it with before you get it cut. Krew comb is available at some walgreens and all sally beauty supply stores. I'd put up more photos but I am limited to ten links. If you need to see more let me know.

Good Luck!