How Wide Should Retail Aisles Be to Prevent the "Butt-Brush Effect"?
Have you ever walked away from a display because the aisle was so narrow that people kept bumping into you? That reaction has a name: the butt-brush effect. It's one of the most common and least visible reasons shoppers leave without buying.
Here's what it is, how wide your aisles should be, and how to fix a store that feels too tight.
What Is the Butt-Brush Effect?
The butt-brush effect is a term associated with retail researcher Paco Underhill, who observed shopper behaviour in stores. The idea is simple: when an aisle is so narrow that shoppers get brushed or bumped from behind by passers-by, they become uncomfortable and often move away from the product they were looking at.
In practice, that means:
Shoppers cut their browsing short in narrow areas.
They're less likely to stop, handle products, or try things on.
Merchandise in cramped spots gets less attention, no matter how good it is.
The effect is about personal space. People are comfortable looking at products only when they feel they have room to do so without being jostled.
How Wide Should Retail Aisles Be?
There's no single legal or universal figure, and the right width depends on the store, the shoppers, and local building and accessibility rules. The following are commonly used guidelines.
Aisle type | Typical width | Notes |
Secondary aisle between displays | About 90 to 120 cm | Enough for one person to browse while another passes |
Main aisle (primary circulation path) | About 120 to 180 cm | Handles more traffic and two-way flow |
Aisle for shoppers with trolleys, strollers, or wheelchairs | About 120 to 150 cm or more | Allows manoeuvring and passing |
Aisle in a high-traffic store (supermarket, big-box) | About 150 to 200 cm or more | Heavy two-way traffic and trolleys |
Absolute minimum clear path | About 90 cm | Often the lowest acceptable accessible width in many guidelines; not comfortable for browsing |
A useful way to think about it: you want enough room for a shopper to stop and look at one side while another person passes behind without touching them. That usually means at least 90 cm of clear path after the browsing shopper's space is taken into account, so in practice 110 to 120 cm or more is more comfortable.
Always check local building codes and accessibility requirements for your location, as these can set minimum widths for circulation and wheelchair access.
What Affects the Right Width?
Store type. A grocery store with trolleys needs wider aisles than a small boutique with hand baskets.
Customer profile. Families with strollers, older shoppers, and customers with mobility aids all need more room. So do stores that sell larger items.
Footfall. Busy stores need wider main aisles to cope with two-way traffic and peak times.
Product type. Where customers browse and handle items, such as clothing racks and gifts, aisles need extra room beyond the walking path. In "grab and go" stores, narrower aisles can work.
Fixture height and depth. Tall fixtures make narrow aisles feel tighter than low ones. A 1.2 m aisle between low displays feels more open than the same width between tall shelves.
Store size. In a small unit, you may need to trade a few fixtures for more open space rather than squeeze everything in.
Why Cramming Hurts Sales
It's tempting to fit as many fixtures as possible into the floor area, because more stock seems to mean more sales. But a tight layout can lower sales when:
Shoppers avoid narrow aisles and miss products.
Browsing time drops, so fewer items are picked up.
Customers with bags, strollers, or wheelchairs can't get through, and leave.
Stock gets knocked or damaged by bumping.
The store feels cluttered and unpremium.
Often, removing one fixture and widening the aisles improves overall sales, because more of the store becomes usable.
How to Fix a Store That Feels Too Tight
Walk it at peak time. Watch where people get stuck, turn around, or avoid.
Remove or reposition one or two fixtures, especially in high-traffic areas or near the entrance and checkout.
Lower the height of fixtures in tight zones so the space feels more open and sightlines improve.
Use narrower, shallower fixtures where you can't widen the aisle.
Reduce depth of wall displays or switch to slimmer shelving.
Simplify the layout. A clear grid or loop with fewer, better-placed fixtures often feels wider than a crowded free-flow plan.
Create pause points. Add small open areas or wider spots so shoppers have a place to stop without blocking the path.
Move high-interest items to wider zones, and put quick-pick items in tighter spots.
Aisle Width by Store Type
Supermarkets and minimarkets: Wider main aisles for trolleys and baskets, with clear space at intersections and near the checkout.
Fashion and apparel: Extra room at racks where customers flip through garments, plus space around fitting rooms.
Boutiques and gift shops: Open, relaxed spaces. Don't overload tables and stands.
Homeware and furniture: Generous paths to move around larger items and view them from a distance.
Pharmacies and clinics: Clear, accessible paths with calm waiting areas.
Small shops: Prioritise a clean single path and fewer fixtures over maximum stock.
Common Mistakes
Treating the minimum legal width as the ideal.
Designing for an empty store, not a busy Saturday.
Placing displays, stands, or promotional bins in the aisle that narrow it further.
Forgetting the width taken up by shoppers who stop to browse.
Putting the busiest items in the tightest spots.
Ignoring accessibility, including turning space for wheelchairs and strollers.
The Bottom Line
To avoid the butt-brush effect, give shoppers room to browse without being bumped. As a practical guide, aim for about 90 to 120 cm for secondary aisles and 120 to 180 cm for main aisles, with more for trolleys, high traffic, or accessibility. Treat these as starting points, check local regulations, and test your layout at peak times. Often the best way to sell more is to put fewer things on the floor and let the rest breathe.
Kita Design Co. (PT Kita Desain Bersama) is a Jakarta-based commercial interior design and build studio working across F&B, retail, clinics, wellness, offices, and sports & fitness spaces. Planning your store layout? Get in touch at www.kitadesign.co.
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