Say you're sold on adding used. The next question is deceptively simple: how much of your floor do you give it? Too little and it never gets the traction to matter. Too much and you've starved the new-goods business that pays your rent. This is one of the most consequential calls you'll make, and most owners make it on feel. There's a better way.
Space is your scarcest asset, so treat it like one
Your store has a fixed number of square feet, and every one of them is already doing a job. When you carve out room for used, you're not adding space, you're reallocating it. The relevant question is never "how much space does used need?" It's "what does this space earn as used versus what it earns today?"
That reframe changes everything. It turns a gut call into a measurable one, using a number you probably already track for the rest of your store: sales per square foot. Whatever a section earns per square foot as new goods is the bar the used department has to clear to justify the same footprint.
Start small and make it earn its expansion
The lowest-risk way in is to start with a modest footprint, a rack, an endcap, a defined corner, and treat expansion as something used has to earn. Give it enough space to be a real department (too small and customers won't take it seriously or find enough to browse), but not so much that a slow start puts a dent in your overall productivity.
Then watch how it performs per square foot. If the used section is out-earning the space it replaced, that's your signal to give it more. If it's lagging, you've contained the damage to a small footprint while you fix the pricing, sourcing, or assortment problem underneath.
Space follows performance, not enthusiasm.
Placement matters as much as size
Where you put used is nearly as important as how much you allocate. A used section tucked in a dead corner won't perform, and you'll wrongly conclude used doesn't work for you. Placed where it pulls customers deeper into the store, or where its treasure-hunt energy catches browsers, it can lift the whole floor by increasing how far and how often people move through it. The best used placements do double duty: they earn their own square footage and they improve the productivity of the space around them.
The signals that tell you to grow or shrink it
You don't have to guess whether the allocation is right. If used is turning fast, holding its sales per square foot, and the racks thin out between restocks, it's ready for more room. If it's turning slowly, aging into markdowns, and dragging its square-foot productivity below what it replaced, it's either too big or has a problem upstream in pricing or sourcing. Read those signals honestly and the right size reveals itself over a season or two, rather than being locked in by a guess on day one.
Where owners go wrong
The two classic mistakes are opposite and equally costly. Some owners give used a token sliver, starve it of the critical mass it needs to build a following, and declare the experiment a failure. Others fall in love with the margin story, hand over a big chunk of prime floor, and watch overall sales per square foot sag when the department can't fill those shoes yet. Both come from sizing on emotion instead of on what the space earns. Size it on the numbers and you avoid both.
Size by sales per square foot, not by feel
The right way to size a used section is the same way you should size any part of your store: by what it earns per square foot, not by a vague sense of how much room it deserves. Every square foot of your floor has a cost and a productivity, and the used section should be judged on whether it generates competitive sales for the space it occupies. If your used goods are turning briskly and producing strong sales per square foot, they justify more space; if they are sitting, they are underperforming the floor they take and should shrink or turn faster before they grow.
This discipline protects you from the two common mistakes: starving a productive used section that could earn more with more room, and letting an underperforming one sprawl because it feels like it should be bigger. Track the used section's sales against its footprint the way you would any department, and let that number drive the size decision. Space in a store is finite and valuable, so allocate it to what earns it, and make the used section compete for its square footage on the same terms as everything else rather than getting a pass because it is new or interesting.
Start small and grow with the numbers
Because the right size is ultimately an empirical question, the smart move is to start small and let performance guide expansion. Begin with a modest footprint, enough to present the section well but not so much that a slow start leaves you with dead space, and expand as the sales per square foot justify it. This ties directly to running a low-risk pilot: a contained section proves both whether used works and how much space it deserves, giving you real data instead of a guess before you commit significant floor.
Growing with the numbers also keeps the section healthy, because a used department that expands only as fast as it can fill with quality, fast-turning goods never develops the stale, half-empty look that kills the browsing appeal. Resist the urge to allocate a large space up front on the assumption that you will fill it; instead, let demand pull the footprint outward. A section that is a little too small and clearly turning is a far better problem than one that is too big and looking thin, so err toward starting tight and earning the space.
Placement matters as much as size
How much space you give used matters less than where you put it, because placement drives whether customers actually encounter and shop the section. A used section exiled to the least-trafficked back corner will underperform no matter how much room it has, while a well-placed section in the flow of your floor will draw shoppers who did not come in specifically for used. Put it where customers will naturally find it, and use signage to draw new-goods shoppers toward it, so the section benefits from your existing traffic rather than hiding from it.
Placement also shapes perception. A used section given a visible, intentional, well-lit spot reads as a real part of the store and signals that you take it seriously, which lifts how customers value the goods, whereas a hidden corner reads as an afterthought regardless of what is in it. This is the same principle that runs through whether used cheapens the brand and through a strong launch: presentation and prominence tell customers how to regard the section. So decide placement with as much care as size, because a smaller section in a great spot will usually outperform a larger one hidden away.
Footprints vary by category
The right footprint also depends heavily on what you sell, because categories differ enormously in how much space a unit of sales requires. Furniture demands significant room per item and staging space, so a furniture section is inherently space-hungry and has to earn strong sales to justify it, which is part of why consignment suits it. Apparel packs many units into a rack and turns on volume, so it uses space efficiently. Books need shelving and organization; electronics need secure, compact display; instruments need room to display and demo.
Match your footprint expectations to your category's nature rather than applying a generic rule, and lean on the category-specific playbooks for how each uses space, from adding a used furniture section to adding a used clothing section. The sales-per-square-foot discipline still governs, but what counts as a productive footprint looks very different for a category of large, high-ticket, slow-turning goods than for one of small, fast-turning ones. Know your category's space economics and size accordingly, so you neither cramp a category that needs room to sell nor over-allocate to one that turns in a small footprint.
Balance used against your new goods
Because floor space is finite, sizing the used section is also a decision about what it displaces, so weigh it against the productivity of the new goods it would replace. The used section should earn its space at least as well as the new goods it pushes aside; if it does, growing it is a good trade, and if it does not, the space is better left to new. This is not a reason to keep used small out of caution, since used often out-earns the new goods per square foot once it is running well, but a reason to make the allocation on the numbers rather than on enthusiasm or fear.
In practice, a well-run used section frequently justifies taking space from underperforming new-goods areas, because its margins and traffic can be strong, but that case should be made with data, not assumed. Watch how used and new each perform per square foot and let the comparison guide where the line between them sits, adjusting as the numbers evolve. Treating the whole floor as a portfolio to be allocated by productivity, with used competing fairly for its share, is how you arrive at the right size for the used section without either starving it or letting it crowd out things that earn their place.
The bottom line
How much floor space a used department should take is not a fixed number but a discipline: size it by sales per square foot, start small and grow with the results, place it where customers will find and respect it, match the footprint to your category's space economics, and balance it fairly against your new goods. Do that and the section will end up exactly as big as it deserves to be, no larger and no smaller, earning its place on your floor rather than taking it on faith. Let the numbers and the customer flow decide, revisit the allocation as the section matures, and you will avoid both the starved-productive-section and the sprawling-dead-space mistakes that trip up stores that size used by feel.
Funkhouser Strategy helps independent and mid-market retailers make the calls that move the P&L, resale included, with senior operator judgment and no vendor agenda.