All Vivos are wide, thin and flexible. This replicates the barefoot condition, allowing your feet and toes space to move freely and splay into a more natural shape This builds foot strength, balance and mobility - toes and arches included!

Strong feet reduce the risk of foot deformities and injuries (Garth et al., 1989; Curtis et al., 2021) and are associated with better balance and stability, especially as we get older (Pink et al., 2011; Cudejko., 2020). Children who run barefoot also jump higher, with shorter contact times (Mizushima, 2020).

Vivos are designed as close to barefoot as possible to realise these benefits - to regenerate your feet.

By giving your feet room to move and splay, wearing Vivos means even adult feet may grow over time. In fact, your feet do keep growing - even without barefoot footwear!

Kids' feet grow between 6 mm and 12 mm (roughly 1 to 2 sizes) per year between the ages of 6 and 16.

Teenagers’ and adults' feet can expand by up to half a size (roughly 3 mm to 4 mm) throughout the day, especially after exercise. Wider, higher and arched feet expand more than narrower, lower and less-arched feet.

Adults’ feet can grow up to half a size per decade, even after the age of 40. 

For these reasons, our sizes and fit recommendations include 6 - 14 mm of toe room (for growth, daily movement and styling).

Because men’s and women’s sizing is different, make sure you use the appropriate chart when measuring your feet.

That said, some people do prefer footwear designed for a different gender. Within EU sizes 40 to 43 - so-called ‘crossover sizes’ - men with narrower feet may prefer the women's equivalent product, and vice versa for women with wider feet. We see this on a daily basis!

So, you’ve measured your feet. But what fit is best? This will depend on your foot width, and/or whether you prefer a snug or spacious fit. 

Your longest toe will probably fall between two size lines - e.g. between sizes 7 and 8. If so, we generally recommend choosing the larger size (in this case size 8). But there are some other considerations.

Our research suggests that if you have narrow feet and/or prefer a snug fit, you may prefer to move down a size (size 7, in this example). Even if you choose size 7 despite your longest toe being very close to the size 8 line, you will still have at least 4 mm of toe room (the recommended minimum).

On the other hand, you may want to consider sizing further up (up to size 9, in our example) if any or multiple of the following apply:

Your longest toe is just below the line (size 8, in our example);
You prefer a more spacious, barefoot fit;
You have wide feet, and have historically found shoes too tight (although remember that Vivos are wider than standard shoes);
You are buying Vivos that can run small (we will clearly note this on the product page for that model).

If, after all this, you’re still in doubt, we generally recommend choosing the larger option. This gives your feet room to grow, move naturally, splay and build strength. 

However, be careful! The risk of tripping and falling increases with longer footwear, so take care if you’re transitioning into a preferred size that’s larger than you’re accustomed to. Lots of Vivobarefoot customers have wide feet and enjoy 20 mm of toe space without a problem, but better safe than sorry.