Perm and Change of Hair Length

Long permed hair
Photo: George Rudy/Shutterstock
Q: Hello. I was just wondering if you could tell me the perfect length to grow my hair, so that when I get a perm, it won't go really short. I would like my permed hair to be at least below my shoulders.
Do you know how much your hair is lifted when you get a perm - for example how much shorter it goes?

A: The degree of change in length, when the hair is permed, is going to be determined by the size of the perming tools used and the strength of the curl achieved. A good rule of thumb for gauging the change is to expect to lose one-third to one-half of the current length depending on the size and strength of the curl.
You can also test the change by asking your stylist to wrap your hair with only water and dry it on the perming tools, then take it down and pull the curls out a bit or moisten the hair slightly to make sure the curls are reasonably loosened since the hair is not typically dried on the tools during a perm procedure. Even so, this can help you get a sense of the change in length that will occur. (If you are getting a spiral perm, you will get a more accurate approximation of the perm results.)
You will also want to keep in mind that curly hair contracts more when it goes from being wet to being dry. The difference in length can be as much as 4 or more inches. So, after your hair is permed, don't expect the length you see when the tools are removed to reflect the exact length that you will have once the hair is dried.
See also:
How much will hair stretch?
How much does hair shrink up when you get a perm?