Run and roam wild
Built for trail running and adventuring closer to nature
The Primus Trail 3.5 FG is for runners who live for the end of the road. These all-terrain trainers are light and flexible enough to move freely, and tough enough to run wild on rough, rocky ground. Made with recycled, vegan*, high-performance materials.
We're on a mission to create a fully circular shoe – a new Vivo made from an old one, which can in turn be made into another. The Primus 3.5 is a big step forward on this journey.
With an already mechanically recyclable outsole, the challenge is making an upper from 100% polyester, which can be recycled. The new Primus Trail 3.5 upper takes us from 34% to 76% polyester, of which 93% is recycled. Why not 100%? Because some parts of the upper still need extra durability that polyester can't yet provide. We’re working with our partners to figure out this final piece of the puzzle.
Fit, Feel, Flex: For natural stability, natural sensory feedback and natural strength.
Vivobarefoot Women’s Size Chart
Ensure the perfect fit with your Vivobarefoot shoes. Our guide provides accurate size conversions (cm, EU, UK, US), the “rule of thumb” toe-room tip, and flexible 365-day returns.
Women’s Footwear Size Guide
| Foot Length (cm) | EU | UK | US |
|---|---|---|---|
| 22.8 | 35 | 3 | 5.5 |
| 23.5 | 36 | 3.5 | 6 |
| 24.2 | 37 | 4 | 7 |
| 24.9 | 38 | 5 | 7.5 |
| 25.5 | 39 | 6 | 8 |
| 26.1 | 40 | 7 | 9 |
| 26.9 | 41 | 8 | 10 |
| 27.5 | 42 | 8.5 | 11 |
| 28.2 | 43 | 9 | 11.5 |
The "Rule of Thumb" Fit Tip
Vivobarefoot intentionally fits larger to give your toes room to wiggle—especially important for natural movement. If you can comfortably fit your thumb between your longest toe and the shoe’s front, you’ve likely found the right size. Over time, as your toes naturally splay, you may need to go up a size.
How to Measure Your Feet
- Stand with your heel against a wall on a hard surface and measure from wall to tip of your longest toe in centimeters.
- Use the “cm” column above to determine your size.
- Measure both feet and base your choice on the larger measurement.
- Measure at the end of the day when your feet are slightly larger.
Sizing Advice & Return Policy
- Vivobarefoot fits liberally—don’t size down to compensate. A bit more room means better barefoot feel.
- If you're between sizes or plan to wear thick socks, consider sizing up for lasting comfort.
- Not completely sure? You have a full 365 days to return unused shoes for a refund or store credit—stress-free returns.
Run and roam wild
Built for trail running and adventuring closer to nature
The Primus Trail 3.5 FG is for runners who live for the end of the road. These all-terrain trainers are light and flexible enough to move freely, and tough enough to run wild on rough, rocky ground. Made with recycled, vegan*, high-performance materials.
We're on a mission to create a fully circular shoe – a new Vivo made from an old one, which can in turn be made into another. The Primus 3.5 is a big step forward on this journey.
With an already mechanically recyclable outsole, the challenge is making an upper from 100% polyester, which can be recycled. The new Primus Trail 3.5 upper takes us from 34% to 76% polyester, of which 93% is recycled. Why not 100%? Because some parts of the upper still need extra durability that polyester can't yet provide. We’re working with our partners to figure out this final piece of the puzzle.
Fit, Feel, Flex: For natural stability, natural sensory feedback and natural strength.
Vivobarefoot Women’s Size Chart
Ensure the perfect fit with your Vivobarefoot shoes. Our guide provides accurate size conversions (cm, EU, UK, US), the “rule of thumb” toe-room tip, and flexible 365-day returns.
Women’s Footwear Size Guide
| Foot Length (cm) | EU | UK | US |
|---|---|---|---|
| 22.8 | 35 | 3 | 5.5 |
| 23.5 | 36 | 3.5 | 6 |
| 24.2 | 37 | 4 | 7 |
| 24.9 | 38 | 5 | 7.5 |
| 25.5 | 39 | 6 | 8 |
| 26.1 | 40 | 7 | 9 |
| 26.9 | 41 | 8 | 10 |
| 27.5 | 42 | 8.5 | 11 |
| 28.2 | 43 | 9 | 11.5 |
The "Rule of Thumb" Fit Tip
Vivobarefoot intentionally fits larger to give your toes room to wiggle—especially important for natural movement. If you can comfortably fit your thumb between your longest toe and the shoe’s front, you’ve likely found the right size. Over time, as your toes naturally splay, you may need to go up a size.
How to Measure Your Feet
- Stand with your heel against a wall on a hard surface and measure from wall to tip of your longest toe in centimeters.
- Use the “cm” column above to determine your size.
- Measure both feet and base your choice on the larger measurement.
- Measure at the end of the day when your feet are slightly larger.
Sizing Advice & Return Policy
- Vivobarefoot fits liberally—don’t size down to compensate. A bit more room means better barefoot feel.
- If you're between sizes or plan to wear thick socks, consider sizing up for lasting comfort.
- Not completely sure? You have a full 365 days to return unused shoes for a refund or store credit—stress-free returns.
15,000+ Reasons to Give Us a Try
At Adventureco, we stand behind every product we sell. That’s why you’re covered by our 365-Day Return Policy — with free returns within Australia.
Not the right fit? Changed your mind? No worries. Return your gear in unused condition within 365 days for a full refund or store credit — no fuss, no pressure.
Trusted for 9+ years and over 15,000 orders delivered. Shop with confidence, the adventure is guaranteed.