How to Find Your Chaco Size

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Chacos are well known for their adjustable straps and bright colors and for being a bit hard to find your Chaco size. The sandals only come in whole sizes, leading to some confusion for those that typically wear a half size. Typically the advice is, if you wear a half size to go down to the next whole size for Chacos. For many people that simple rule of sizing will get them in the right Chaco size. However sizing Chacos is much more than just going down to a whole size. Chacos are sized by the heel-to-ball measurement instead of overall foot length like most shoes.

Shelemah chaco feetOur feet are the foundation of our entire bodies. No amount of chiropractic care, yoga, organic food, supplements, or other health practices can make up for an unstable foundation. Proper fitting footwear and a well supported arch  are the building blocks of whole body health so getting the right size Chacos is super important.

When I was in undegrad and grad school, I worked as a footwear specialist at REI.  While it’s been several years now since I donned a green vest and had the nickname “Chaco Queen”, my passion for Chaco sandals and properly fitting footwear has never left me. So without your foot in front of me to measure, here is my best online  attempt to show you how to find your Chaco size.

How to Find Your Chaco Size

Measuring with a Brannock Device

heel to ball measurement

As you can see in this lovely photo of my foot. My overall foot length is just a smidge over 8.5 and my heel to ball measurement (right arch length on the Brannock device) is just a smidge under 8.5. My foot width is a solid B, narrow to regular width.

What all this translates to with Chacos is that the typical “go down to the nearest whole size” recommendation is correct for me. So my Chaco size is an 8 even though I typically wear an 8.5 in other shoes.

Any well trained footwear staff should be able to measure all this for you, but you can also measure yourself. The Brannock device has been around for decades as the measuring standard for footwear and is simple to learn to use.


Your Toes Will Fit

When I first bought a pair of Chacos, and knew none of this important information, I got a size 9 because I didn’t want my toes to hang off the edge of the shoe. Unfortunately, because a 9 arch length is too long for me that first pair of Chacos was never comfortable and would hurt my arch and heel after wearing them for a little while.

size 9 chacos

Size 9 with a good half inch of space between my toes and the edge of the shoe.

Size 7 chacos

Size 7, clearly too small and my toes are hanging off the edge.

size 8 chacos

Size 8, perfect fit.








Despite my initial fear that 8’s wouldn’t give my toes enough room, they fit perfectly and I have never had an issue with hitting my toes while wearing my Chacos. If you’ve ever seen someone wearing Chacos and thought they looked big and clunky they probably were wearing too large a size. Properly fitting Chacos should hug your foot and not add bulk.


Luvseat Orthopedic Footbed

Chacos are made with their patented Luvseat orthopedic footbed which is certified by the American Podiatric Medical Association. What that means is that the APMA has found the footbed to promote good foot health. When I worked at REI we had some local podiatrists that would send people to use to get fitted for Chacos because they help alleviate plantar fasciitis as well as some other common foot issues.

The reason heel to ball measurement is so important for Chacos is the way their orthopedic footbed cups the heel and supports the arch. Your foot has 26 bones and 33 joints. A few of those joints are especially important to support so that your foot is stable, preventing pronation or supination.

Subtalar Joint

The highest point of the arch on a Chaco footbed should be supporting the subtalar joint. A good way to tell if it is hitting in the right place is to imagine a line going straight through your foot from the front of your ankle. The reason the size 9’s hurt my feet is the arch of the footbed was hitting too  far back on my foot. The support was behind the subtalar joint instead of right under it.

size 8 subtalar

Size 8 Chacos showing where subtalar joint is supported

Size 9 Chacos showing how support is too far behind subtalar joint. Not providing proper support.








Heel Cup

Our heels have a nice pad of fat that provides natural cushion. The Chaco Luvseat  footbed cups your heel so that cushion is maximized for all day comfort. This is why getting the proper width Chacos is so important. If the shoes are too wide the heel is not cupped, and the cushion is diminished. Your heel can also slide around side to side leading to decreased stability. If the shoe is too narrow not only will the heel be uncomfortable, but the arch will hit in the wrong place and the straps will be too tight no matter how much you adjust them.

Another reason you may look at trying a wide Chaco size is if your overall foot length and your heel to ball differ by a whole size and the heel to ball is smaller. The wide size Chacos are a little bit longer than the mediums without changing the arch length. So if you are a size 8 heel to ball and size 9 over all foot length, an 8 wide may actually give you the best fit. Just be sure that your heel is not loose and sliding around in the wide.

Chaco sizes are marked on the back of the heel of each shoe. A dot means it is the regular width, a dash means it is a wide. The M or W by the size number stands for Men’s and Women’s. When Chaco’s first came out they had medium and narrow as their widths. When they changed over to medium and wide they didn’t change the size run, they just changed the labels. So even if you do not typically wear a wide shoe, you may be a wide in Chacos.

chacos size 8 wide

Size 8 wide, see all that extra room on either side of my heel.

chacos size 8 regular

Size 8 regular, perfectly snug fit.








Ajustable Straps

how to adjust chacos

The straps on Chacos are totally adjustable, which enables a perfect custom fit. Even with adjustable straps though, it is still important to get the right size so that the straps hit your foot in the right places. There are tons of great resources out there showing you exactly how to adjust Chacos. Here are my tips for adjusting the straps:

  • Use fabric softener to loosen up a stuck strap, put a little at the base of the strap and floss back and forth till it loosens up.
  • Readjust straps after the first two weeks of wearing them to get the perfect fit
  • Loose is better, there’s no need to get them super tight, just tight enough to stay put it is perfect
  • The heel strap doesn’t adjust. But if you have the right size and the straps adjusted well the heel strap will fit well. It doesn’t need to be super tight, it’s there as a back-stop to keep your foot from sliding off
  • Stay away from sand! The quickest way to ruin a pair of Chacos is to get sand inside the footbed with the straps. The sand rubs at the straps until it cuts straight through them.

This post was not sponsored by anyone. As much as I love REI and Chaco and am sure they love me too, they did not ask me to write this post and have not compensated me in any way.

Are you wearing the right size Chacos? Learn how to find your Chaco size and know if you should go up or down with a half size #chaconation #chacos

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