Direct Answer

Same-store sales measures the percentage change in sales at restaurant locations open for a comparable period, typically at least one year, isolating organic growth from growth driven by opening new locations. Unit economics measures the profitability of a single restaurant location -- commonly through average unit volume (revenue per store) and restaurant-level operating margin -- used to judge whether a concept is profitable enough at the store level to support healthy returns as the company expands.

Key Takeaways

  • Same-store sales (also called comparable-store sales) excludes recently opened restaurants so the figure reflects performance at stores that have already had time to establish a normal sales base.
  • A restaurant needs at least a full comparable period, typically one year, of operating history before it is included in the same-store sales calculation.
  • Unit economics is commonly assessed through two figures together: average unit volume (revenue per store) and restaurant-level operating margin.
  • Positive same-store sales growth and healthy unit economics are related but distinct questions -- one tracks direction of change, the other tracks the absolute level of store profitability.
  • Unit economics is used to evaluate whether a chain's growth-through-expansion strategy is likely to produce profitable new stores, not just more stores.

How Are Same-Store Sales and Unit Economics Calculated?

Same-store sales compares sales at a defined set of restaurant locations across two comparable periods, expressed as a percentage change. The comparable set is limited to stores that have been open for at least a full comparable period, typically one year, so that a location's first months of ramping traffic do not distort the figure. New locations opened during the measurement period are excluded from the calculation until they, too, have accumulated a comparable operating history. This structure means same-store sales growth can come from higher traffic (more transactions), higher average check (more spent per visit), or a mix of both -- but it deliberately does not capture the effect of adding entirely new locations.

Unit economics, by contrast, is not a single formula but a framework built primarily around two figures. Average unit volume (AUV) is the revenue generated by a typical restaurant location over a given period, most often measured annually. Restaurant-level operating margin is the profitability of that same location after subtracting store-level operating costs -- such as food and labor costs and occupancy -- from its revenue, generally before corporate overhead and other costs that sit above the individual store. Together, AUV and restaurant-level operating margin describe whether a single store, on its own, produces an attractive return relative to what it cost to open and run.

Worked Example

Hypothetical example -- for education only.

Consider a restaurant chain evaluating one of its mature locations that has been open for more than a year and is therefore included in the comparable-store base.

Unrecognizable male in casual clothes standing with money near cash register in grocery store while making purchase near glass showcase
Photo by Tim Samuel via Pexels
  • Sales in the comparable period a year ago: $2,000,000
  • Sales in the current comparable period: $2,100,000
  • Same-store sales change: ($2,100,000 − $2,000,000) ÷ $2,000,000 = 5.0%

Now consider the same location's unit economics for the current period:

  • Average unit volume (revenue): $2,100,000
  • Restaurant-level operating costs (food, labor, occupancy, and other store-level expenses): $1,785,000
  • Restaurant-level operating profit: $2,100,000 − $1,785,000 = $315,000
  • Restaurant-level operating margin: $315,000 ÷ $2,100,000 = 15.0%

In this illustration, the location posted 5.0% same-store sales growth and carries a 15.0% restaurant-level operating margin on $2,100,000 of average unit volume. Both figures matter for a different question: the same-store sales figure describes the trend at this store, while the AUV and margin figures describe whether the store's current level of profitability is healthy enough to make opening more locations like it a good use of capital.

Limitations and Common Mistakes

  • Confusing same-store sales with total revenue growth. A chain can report strong total revenue growth driven almost entirely by new-unit openings while same-store sales at existing locations are flat or declining -- the two figures answer different questions.
  • Treating same-store sales growth as proof of healthy unit economics. Positive same-store sales growth describes the direction of change; it does not by itself say whether a store's restaurant-level operating margin is strong, thin, or negative.
  • Ignoring how the comparable-store window is defined. The specific length of the comparable period and which locations are included can vary by company, so figures are not always perfectly comparable across chains without checking the underlying definition.
  • Overlooking cost inflation behind the margin. A location can grow AUV while restaurant-level operating margin compresses if food, labor, or occupancy costs rise faster than revenue -- the margin figure, not revenue alone, reflects that tradeoff.
  • Assuming unit economics are uniform across a concept. AUV and restaurant-level operating margin commonly vary by format, market, and store age, so a single chain-wide average can mask meaningfully stronger or weaker individual locations.

Frequently Asked Questions

What is same-store sales for a restaurant chain?

Same-store sales measures the percentage change in sales at restaurant locations that have been open for a comparable period, typically at least one year. By excluding recently opened locations, it isolates organic growth -- more traffic, higher prices, or better mix at existing stores -- from growth that simply comes from opening new units.

What does unit economics mean for a restaurant company?

Unit economics refers to the profitability of a single restaurant location, commonly assessed through average unit volume (revenue per store) and restaurant-level operating margin. It is used to judge whether an individual store generates enough profit to justify the capital spent opening it, and whether that profitability can support healthy returns as the company adds more locations.

Why do investors watch same-store sales instead of total revenue?

Total revenue can rise simply because a chain opened more restaurants, even if the existing locations are struggling. Same-store sales strips out that new-unit effect, so it commonly serves as a more direct signal of whether the underlying concept is resonating with customers at stores that have already had time to mature.

What is average unit volume (AUV)?

Average unit volume is a measure of revenue generated per restaurant location, typically calculated over a trailing period such as a year. It is one of the two components commonly used to assess unit economics, alongside restaurant-level operating margin, and it varies by concept, format, and market.

Can a restaurant chain have strong same-store sales but weak unit economics?

Yes. Same-store sales measures the direction of change in comparable-store sales, while unit economics measures the absolute level of store profitability. A chain can post positive same-store sales growth while individual stores still carry thin or negative restaurant-level operating margin if costs are rising as fast as, or faster than, sales.

How does unit economics relate to a restaurant company's expansion plans?

Unit economics is used to assess whether a restaurant concept is profitable enough at the store level to support healthy returns as the company expands. Weak restaurant-level margins or low average unit volume at existing stores generally raise the question of whether opening additional locations will produce comparably profitable, or worse, results.

How is restaurant same-store sales split into traffic and average check?

The change decomposes into how many transactions occurred and how much each one was worth. Growth driven by traffic indicates more guests are visiting. Growth driven by check can come from menu price increases, from guests ordering more items, or from a shift toward higher-priced items. Price-led growth during a period of cost inflation is common and not automatically a weakness, but sustained traffic declines masked by price increases is a distinct and less durable pattern.

What is cash-on-cash return for a new restaurant location?

It compares the annual cash flow a location generates against the cash invested to open it, covering build-out, equipment, and pre-opening costs. Companies present it to argue that expansion creates value, since a new unit only earns its cost of capital if the return clears it. The figure typically reflects a mature-year estimate rather than the first year, and it usually excludes corporate overhead, so it describes unit-level attractiveness rather than the return to shareholders.

How do franchised and company-operated units change the reported economics?

A franchised location produces royalty and fee income for the parent rather than restaurant sales, so revenue is much smaller while margin is much higher, and the operating costs sit with the franchisee. A heavily franchised chain therefore shows a different margin structure from a company-operated one with the same consumer footprint. System-wide sales, which include franchised locations, are the figure that describes total consumer activity, and it is not the same as reported revenue.

References

  • SEC EDGAR -- full-text search of restaurant company 10-K and 10-Q filings, which commonly disclose same-store sales and unit-level economics definitions and figures.
  • Company 10-K and 10-Q filings generally -- the primary source for how a given restaurant chain defines its comparable-store base, average unit volume, and restaurant-level operating margin.