RadiusMapperDefinition
Catchment area
Also known as: Catchment zone, Draw area, Market area
A catchment area is the geographic zone from which a business or institution draws its customers, patients, students, or residents. It is the inbound counterpart to a service area.
A catchment area is the analytical framing of a drive-time polygon: the zone from which customers reach the business, rather than the zone the business reaches out to. Catchment areas are used for market sizing, demand estimation, and site selection. Retail and QSR typically apply a 70/20/10 rule: roughly 70 percent of customers come from the primary ring, 20 percent from the secondary, and 10 percent from the tertiary. Healthcare, education, and civic planning use catchment areas with different thresholds to estimate who is served by a given facility.
Key characteristics
- Retail catchment: 70/20/10 — 70% primary ring, 20% secondary, 10% tertiary.
- Grocery catchment: typically 3-5 miles or 10-15 minutes.
- QSR and fast food: 1-2 miles or 5-10 minutes.
- Hospital catchment: 30-60 minute drive times for general care, wider for specialty.
- School district catchment: defined by residential address, not drive time.
Common use cases
- Retail and restaurant site selection
- Demand estimation with demographic overlay
- Healthcare access analysis
- Academic study of service-delivery equity
How it compares to related terms
Frequently asked about catchment area
What is a catchment area in retail?
In retail, the catchment area is the zone from which a store draws its customers, typically split into primary (50-70% of customers, 1-3 miles or 5-10 minutes), secondary (15-25%, 3-7 miles or 10-20 minutes), and tertiary (5-10%, beyond 7 miles) rings. Catchment area analysis is the foundation of retail site selection.
How do you calculate a catchment area?
A catchment area is usually built as a drive-time polygon (or walk-time for urban retail) rather than a distance circle. You then overlay demographic data — households, income, age — inside the polygon to estimate the addressable market. Competitor location overlays then indicate how much of that market is already captured.
What is the 70/20/10 rule?
The 70/20/10 rule is a retail heuristic: roughly 70 percent of a store's customers come from the primary catchment ring, 20 percent from secondary, and 10 percent from tertiary. It's a starting benchmark rather than an absolute law — destination retail (big box, specialty) skews to longer drives, while convenience retail skews tighter.
Is a catchment area the same as a market area?
Close but not identical. A catchment area is typically the zone from which a specific location draws customers. A market area is broader — it's the geographic market in which a business competes, often covering multiple potential catchment areas.