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Calculating the amount of hair needed for a reroot

Whether you want to improve or repair the appearance of your dolls’ hair, rerooting is the most fundamental way to change the way it looks. Dolls can be rerooted with any kind of “string” type fiber. If it looks or can pass for hair, you can use it. If you’ve got patience and dexterity, you can even use wire. Like this gorgeous Robecca by Mike Valentine.

This article explains how to calculate the amount of Saran or Nylon hair to use for different kinds of reroots. Saran and Nylon are used on factory-made dolls and are available at suppliers like Dollyhair and Restoredoll so colors or blends can match those used by Mattel, Bratz, My Little Pony and many other doll companies.


 Jeanie Ashe

Saran is my personal favorite for rerooting. The strands are thin and allow for a more natural look on dolls. It has low heat sensitivity which means curls will last longer after styling. It’s soft and really easy to work with.


Mugi Aislin Sakura

Probably the most popular type of synthetic hair fiber due to the various color choices. Nylon is a “color scavenger” so it will actively soak in dye if you want to create a tie-dyed effect or want to change the color entirely.

Nylon looks waxy and very “plastic” which gives it a somewhat of a fake appearance. However, the colors are much more vibrant by comparison to Saran. The strands are a little bit thicker than Saran so get used to using less when rerooting. It’s ideal for short hair or elaborate hair.

Unlike Saran, Nylon has a very high heat sensitivity which makes it very easy to style but can just as easily come undone if left in one position for too long or anywhere near a warm area, like a sunlit shelf.

One little downside to Nylon is that some color blends, reds, and blues, in particular, have been observed to “stain” vinyl. It’s rare, but it does happen. Hand-dyed Nylon hair is especially suspect since the dye may not have set during the dye process.

Hanks and Skeins

Saran and Nylon come in Hanks (if you purchase from Dollyhair) and Skeins (if you purchase from RestoreDoll). Hanks and Skeins are the untouched form of Saran and Nylon and are how they come straight out of the factory. Use these measurements as a guideline, not a standard. Make a note of the Hank or Skein length and weight if you plan to get Saran or Nylon from another source.

Note: These measurements are found on Dollyhair and Restore Doll’s websites. Be sure to check their websites before you make a purchase to ensure that the information is up to date since it may have been changed at the time of this article’s writing.

Dollyhair Hanks

38” hanks

Dollyhair sells hair which calculates hair amount for Barbie and Gene with the hair length factored in.

6.3 inches -short
just below shoulders (3.15 inches)
9.5 inches -medium
middle of butt (4.75 inches)
19 inches -long
mid-calf (9.5 inches)
Gene/Tyler etc.
6.3 inches -short
just touching shoulders (3.15 inches)
Gene/Tyler etc.
9.5 inches -medium
middle of waist (4.75 inches)
Gene/Tyler etc.
19 inches -long
just above knees (9.5 inches)
see “info” button below
38″ RD hank
see “info” button below

RestoreDoll Skeins

Standard: Two 18″ inch skeins and weigh .5 oz each. (Enough to reroot a Barbie Doll)
Large: Two 21″ inch skeins and weigh 1 oz each. *
XL Extra Large: Two 31″ inch skeins and weigh 1.5 ounces each.

* The Large format is my favorite and something I recommend for beginners. You either end up with “just enough” for a Barbie doll that has ankle length hair or “just a little bit” left over. It’s ideal to have just a bit left over to do retouch work than not to have enough hair. The worst case scenario is when the hair color you want is no longer available. Having the longer length also gives you the option of trimming the hair length to just below the knees (standard length for dolls with voluminous curls designed to be at waist length). Waist length hair can be achieved just by using 1 skein cut in half.

Sizing up the head

One 38” hank/skein is enough for 1” worth of a doll head circumference, assuming you intend to reroot a doll who has 38” long hair length. If you wanted to reroot a doll with 19” (A 38” hank/skein folded in half) with a head circumference of 4” around, you’ll need 4 hanks/skeins.

Using RestoreDoll’s format:

Standard: 18” skein and weigh 1 oz = 9” length hair on Barbie (4” head circumference)

Large Format: 21” skein = 10.5” length hair on Barbie

XL Extra Large: 31” skein = 15.5” length on Barbie

Keep in mind that when using the reroot tool or Knot method that you’re going to loose at least half an inch of hair length.

We’re using Barbie as a reference for measurement since there are a lot of dolls who share the same exact head circumference and size. But what about dolls that have a slightly big head circumference? What if it’s a doll of an entirely different scale? Get your measuring tapes out!

Wrap a tape measure around the circumference of your doll’s head just behind the ears and across the forehead. Measurement should be in inches.


Make a note of how long the hair length is starting from the top of the doll’s head. Rerooting a bigger doll needs more hanks or skeins with longer length.


Each inch of the head circumference is equivalent to one 38″ hank or skein’s width. Measuring the length will allow you to calculate how many times you need to fold the skein to get the desired length.

Special Thanks to:

Further Reading

This Post Has 23 Comments

  1. Just getting into learning about this and am wondering apx how many strands up hair are you using for each plug? I read you don’t want to make too big or you can “strip” the hole, but having a hard time telling about how much they are using in the videos. Also when people reroot do they use/follow the same holes that are already there or is it common to add more holes for more volume? Lastely part of why I want to do this is because all of our MH dolls have horribly greasy hair from the glue inside, when you reroot and use glue will the same thing happen again or do they use a different type of glue on production that is so horrible? Thanks! This is some of the best info I have found!

    1. I can’t give a straightforward answer as to how many strands I use per plug since it really depends. I highly recommend reading this article which covers that dilemma and other variables you need to consider in detail:

      I will use existing plugs for rerooting and skip some (my reason is covered in detail in that article above). I will add holes if necessary. I’ve never felt the need to add more hair for volume since strategically planning and placing hair pretty much does wonders. Bonus article on that topic:

      I am aware of the glue issue with more recent Mattel dolls. There was some discussion in Tumblr how some customizers noticed that dolls manufactured in China usually have this issue. My own remedy for this is to pop the head out, pour boiling hot water inside the head and hope that fixes it. If you’re unlucky to get the kind of dolls that used a waxy type that doesn’t actually dry and melts as a result of using boiling water, wait for the head to dry completely and reapply your preferred type of glue (I recommend Aleen’s fabric glue), to hold the hair. You could also get lucky in that pouring the boiling water actually helps the existing factory glue harden but watch out for any loose strands if that is the case. Please make sure to be cautious and be super duper careful when you are handling boiling water. Please take every precaution to ensure that you aren’t going to get hurt. I usually do this method in a sink with the doll head secured by a bowl or waterproof container that will hold the head firmly in place. You can test how the head reacts to having water poured on it before you actually try boiling water.

      Keep in mind that the boiling water method will remove any existing curls or waves on the hair so you’ll need to re-do that once you’re satisfied with the hair’s condition later on.

      1. Thank you so much for the answer. I will read through your site and your blogs, lots of info here. We have tried many things for the glue including boiling water and some of them are so bad that nothing seems to help. Have a few I can play around with to learn on so starting there, with yarn. Thanks for the help and info!

  2. HI! How many Hanks should I buy from to fully reroot my MH ghoulia doll? I am having them mix two colors for me but how much would I need for it to be about just under the knee or so?

    1. Make sure to read the article again on how to do the calculation. I’m not going to hold your hand. =P

      It’s been a while since I’ve done any rerooting but Monster High heads usually took me about 1 and 1/2 BARBIE amount from Dollyhair. You should contact Tina from Dollyhair to get the specifics on how much you will need since she can actually check the fiber you’re interested in and give you input on how much amount you actually need to use.

  3. So i have a 8 inch tall mlp with a 10 inch head circumference i want her to have fairly long hair about how much nylon hair would i need for a reroot?

  4. I want to reroot my Little Miss No Name doll, I want to use two colors, maybe a orange and blond, how do I do this, every other hole or every other row, what would make it look nice like highlights. thanks, PattieAnn

    1. You might want to ask the vendor this question since they would have more knowledge on specific rerooting patterns or styles. If you’d like to experiment, it’s good to look at how Monster High dolls are rerooted. They have such a huge variation that there’s bound to be one doll whose look and style closely matches what you’re going for. You can use what you observe as a template.

  5. I’m so confused. I’m going to re root a ever after high doll and I don’t know how many bags of hair I’ll need
    Could you please tell me ?

      1. If the Hank of hair is 1 foot long. how many Hank’s would I need to re root an ever after high doll ?

        1. One hank/skein is enough for 1” worth of a doll head circumference, assuming you intend to reroot a doll who has 1ft long hair length. If you wanted to reroot a doll with half a foot (A foot long hank/skein folded in half) with a head circumference of 4” around, you’ll need 4 hanks/skeins.

          Please re-read the section on “sizing up the head” on how to measure your doll’s head.

          1. So if I want to re-rooting the doll with thd 1ft hair length I would just need one hank ?

  6. Tina from Dollyhair here! Saffy, I don’t know when you placed your last order, but we have been stringently weighing ALL of our hanks. You said that our hanks were weighing 8-9 grams, and I don’t know which size hanks you are referring to, but our saran RD hanks weigh 11.5 grams.

    1. So I want to try a different method. A Youtuber I like, Sugarcharmshop, makes poseable polymer clay character dolls, and for the hair she simply glues it to the head in little sections using Tacky Glue. I want to try this on a Pullip doll (Pullips have a 1/3 scale or 9″ head on a 1/6 scale body), how much hair would I need if I want it to fall to just above her waist? is a picture of the doll with measurements in centimeters. I know for rerooting hair you need twice the length per strand as the final length on the doll will be, so I would need half of that.
      Pullip dolls are NOT rerootable, the scalp is made of hard plastic with no holes. I don’t want to use a wig for fear of covering the mechanisms on the back of the head that make the eyes move and close.

      1. I think you can probably, safely apply the same principle but base it on the wig cap that you’ll be using.

        I’ve heard from folks who customized the 17″ Frightfully Tall ghouls that the heads use the same size wigs as Pullips. Coincidentally, TheDollPlanet ( recommends that you can use their 5oz packs to reroot/rewig. I don’t know if the hair length stays the same or changes based on the amount. You’ll need to contact them to verify.

  7. For the folks who use metrics, here’s my own cheat sheet (for the tool method aka hair folded in half and for saran – though I use the same amount of nylon as it tends to be lossy during prep/work).

    To calculate the size and number of hanks / skeins to buy :
    It takes 3 + 1 half (about 40g) , cut in half , to cover a 5/6″ head with very long hair.

    1 “hank” of Retrodolls saran is about 90cm and 12g therefore:
    A hank can be cut in 3 = length on the doll 14cm max from roots to ends. 2 hanks per reroot.
    A hank can be cut in 2 = length on the doll 20 – 22cm. 4 hanks per reroot.

    1 “Skein” of Mylittlecustoms/Restoredoll saran is 46cm and 12g, it contains as much hair as a hank but it is shorter.
    4 skeins for a reroot = length on the doll 23 cm.

    1 “XL Skein” of Mylittlecustoms/Restoredoll saran is 76cm and 40g, it contains approx. 3 and 1/3 hanks/skeins of fiber.
    1 whole reroot (Cut in 2) = length on the doll 19cm.

    1 “Large Hank” of Retrodolls saran is 90cm and 50g (contains just over 4 hanks)
    1 “XL Hank” of Retrodolls saran is 90cm and 100g (contains 8 hanks)

    // Not using dollyhair hanks any more as they were averaging 8-9g.
    // See for the colour matches between sellers.


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