Vivobarefoot: fit, sizing and the volume problem

Vivobarefoot is the brand the rest of the category is measured against, and the Primus Lite III is why: a 2 mm sole with 2 mm of tread, under 8 oz, on a last that is actually shaped like a foot rather than a narrower shoe that has been widened. If you want to know what the thin end of this category feels like, this is the reference point.

Barefoot shoe discussion is dominated by width, and Vivobarefoot is wide. What it is not is voluminous. The last is low through the instep, and that is a separate dimension from forefoot width — a foot can be broad across the toes and still have a high arch and a thick midfoot, and that combination is where Vivobarefoot fails. The symptom is not cramped toes; it is pressure across the top of the foot and a shoe that feels like it is being pulled over something.

Instep volume is the most under-documented dimension in footwear generally, and it is the reason two people can describe the same shoe as roomy and unwearable. If you have a high instep, read the volume row in the table below as the deciding line on this page.

Four millimeters of total stack is a large step from a cushioned shoe with a raised heel, and the adaptation it demands is real. The documented risk in this category is bone stress injury from moving too fast, and a near-zero-stack shoe gives you the least margin for that error of anything you can buy. Start thicker and work down. The transition plan.

That is not a criticism of the shoe. It is the same reason you would not start a running program with a race.

Vivobarefoot publishes per-model internal length measurements, which is genuinely more useful than a conversion chart and more than most of the category offers. Use it: compare your measured foot length directly to the stated internal length of the specific model you want, and add your clearance from there. Converting from your usual US or EU size is the route to an exchange.

Toe-box width is only half the question — the other half is shape, because a square-toed foot in a tapered toe box is cramped at the little toe even when the shoe is genuinely wide. On the published fit data, Vivobarefoot suits the following toe-length patterns best. How to identify your own foot shape.

• Egyptian (tapered) — A toe box that tapers - but tapers to the OUTSIDE, following your diagonal, rather than squeezing toward a center point. In a square or symmetrically rounded toe box you get space you cannot use at the little toe while the big toe still reaches the end.
• Roman (even first three) — Width across the front third of the toe box specifically, with a generous big-toe allowance. A tapered toe box pushes toes two and three inward against the big toe, which is what starts the overlapping-toe problem.
• Square (near-equal toes) — A genuinely square, foot-shaped toe box with full width carried right to the front. Almost every conventional shoe fails this shape, and so do several 'wide' barefoot shoes whose width is in the midfoot rather than at the toes.

Vivobarefoot publishes per-model internal length measurements, which is more useful than a size chart - compare your measured foot length to the model's stated internal length rather than converting sizes.

The method that works for every brand on this site is the same: measure heel to longest toe in millimeters, on both feet, standing, late in the day. Then compare that figure against this brand's own internal-length data rather than converting from the size you usually wear. How to measure your feet · the cross-brand sizing table.

The roundups that feature Vivobarefoot, so you can see how it ranks against the alternatives rather than taking a brand page's word for it:

• Best barefoot shoes
• Best barefoot sneakers
• Best barefoot hiking shoes
• Best barefoot hiking boots
• Best barefoot shoes for the office
• Best barefoot shoes for narrow feet