Sales per Square Foot: How to Measure It Tenant by Tenant

A leasing manager and a tenant sit down for a renewal. The leasing manager's spreadsheet says the unit does 420 per square foot. The tenant's regional director says 510. Both are right. One divided by gross leasable area, the other by net selling area, one included VAT, the other did not, and one quietly dropped click-and-collect orders that were fulfilled through the store. The conversation that follows is about arithmetic, not about rent.

Sales per square foot is the simplest of the retail kpis on paper and one of the hardest to get consistent across 120 tenants in practice. The trouble is almost never the formula. It is the definitions, the collection and what you place next to the number once you have it.

Decide which square feet you mean, and write it down

Before a single turnover figure is collected, the denominator has to be fixed per unit. Most centres have at least three area figures floating around for the same shop: the demised area in the lease, the GLA figure in the asset register, and whatever the tenant's own planogram says is selling space. A fashion unit with a large stockroom and a mezzanine office can show a 25 percent gap between demised and selling area. Measure that tenant on GLA and they look weak against a kiosk-style operator with no back of house at all.

There is no universally correct choice. What matters is that the same basis is used for every tenant in a category, that it is recorded against the unit in the tenant database rather than remembered by one analyst, and that it is updated when a unit is split, merged or extended. Centres that benchmark on demised area for rent decisions and on selling area for merchandising discussions should label the two indices differently so nobody mixes them in a board paper.

Then define what counts as a sale

The numerator causes more disputes than the denominator because money is attached to it. If your leases carry percentage rent, the turnover definition in the lease is the one that governs, and your reporting system needs to mirror it exactly. If the leases are silent, you still need a house standard. The points that most often diverge between tenants:

• VAT included or excluded. A centre with tenants in both camps is effectively comparing two different currencies.
• Returns and exchanges. Gross takings or net of refunds, and net in which period: the week of sale or the week of return.
• Online orders collected or returned in store. Many retailers credit these to the web channel; from a landlord's point of view the footfall and the staff time happened in the unit.
• Gift cards. Counted at sale, at redemption, or both, which double counts.
• Services, concessions and sub-let counters inside the unit, which may be reported by a different legal entity.

A one-page reporting standard sent with the onboarding pack settles most of this. The remaining cases are negotiated once and documented against the tenant record.

Collection: three routes, and why mixing them is fine

A centre with 150 tenants will not get all of them onto one reporting method, and it does not need to. In VemTenant, which Vemco Group has run alongside its footfall counting since 2013, turnover reaches the centre in three ways. An independent with a single till types the figure in manually, roughly two minutes a day, week or month depending on what the lease requires. A mid-sized chain exports from its POS and drags an Excel or CSV file into the portal, or schedules an SFTP push from head office so nobody has to remember. A national anchor connects directly through the POS vendor's API or Vemco's REST API, which takes around an hour of setup per tenant and then needs no human involvement at all.

The point is that all three land in the same table, against the same unit, with the same area basis and the same turnover definition applied. The mall team stops chasing emails and starts looking at exceptions: who has not reported, whose figure moved more than 40 percent week on week, whose unit area changed without the register being updated.

The number means little until footfall sits beside it

Sales per square foot on its own tells you how much a unit sells. Foot traffic data tells you how many people the centre delivered to that part of the building. Put them together and a flat sales figure splits into two very different stories. A tenant whose density is stable while traffic past the door rose 12 percent is converting less and has a store problem. A tenant whose density fell while traffic on their mall fell 15 percent has a location problem, and that is partly the landlord's to solve.

This is where tenant-level benchmarking earns its keep. Each tenant sees its own index against its branch and against the centre, its ranking within the category, and its turnover trend plotted next to footfall for its zone. Tenants who see a fair comparison report more willingly, because the data is doing something for them rather than only for the rent review. Footfall counts underpinning this are contractually at least 96 percent accurate and typically land between 98 and 99 percent where lighting, entrance layout and visitor behaviour allow, which is more than precise enough for trend and index work.

What you can actually decide with it

Density benchmarks have moved. CBRE reports that US retail sales per square foot rose 26 percent nationwide since 2019, driven by smaller formats, store closures and inflation. A tenant whose density is flat over that period has fallen behind the market even if their absolute turnover looks healthy, and a percentage rent threshold agreed in 2018 may now be far below where it should sit.

Tenant-by-tenant density supports four decisions directly:

• Renewal terms, where occupancy cost ratio (rent plus service charge divided by turnover) rather than headline rent tells you whether a tenant can afford what you are asking.
• Remerchandising, where a dense operator in an undersized unit and a sparse operator in an oversized one can both be fixed by swapping or resizing.
• Marketing allocation, where the question becomes which zones convert visitors rather than which have the most of them.
• Percentage rent audits, where a reported figure that undershoots both the category index and the zone's footfall trend is worth a second look.

One thing implementers learn the hard way

Tenants revise figures. A week's turnover reported on Monday is corrected on Thursday when a refund batch posts, and corrected again at month end when head office reconciles. If the system allows open-ended back-dating, the centre index you presented to the board in April will not match the one you pull in July, and nobody will trust either. Set a lock period in the reporting rules, 30 days is common, after which changes require a mall-side approval and an audit note. The first three months of any new rollout also look strange because tenants are still learning the definitions, so do not set percentage rent thresholds or renewal strategy on that early data.

Frequently asked questions

How do you calculate sales per square foot? Divide a tenant's net turnover for the period by the area of the unit, using the same area basis (demised, GLA or selling area) for every tenant you compare. Annualise the result if you want to benchmark against published figures, since most industry data is quoted per year. The calculation is trivial; the consistency of the two inputs is where the real work sits.

If your tenant turnover currently lives in emailed spreadsheets with three different area bases and no footfall beside it, contact Vemco Group at https://vemcogroup.com/contact-us to see how VemTenant standardises tenant sales reporting across manual, file and API routes and benchmarks every unit against its category and the centre.