Walking Radius Calculator
The distance a walk of a given number of minutes covers, the straight-line radius that corresponds to it through a real street network, the area inside that radius and the population it contains at a given density — the arithmetic of the 15-minute city.
People walk about 4.
How the walking radius calculator works
People walk about 4.5–5 km/h, so 15 minutes is roughly 1.2 km along the streets. Streets do not run straight, so the crow-flies radius is that distance divided by a detour factor (1.2–1.4 in a grid, 1.5–2 in cul-de-sac suburbs). The catchment is the circle of that radius, and multiplying by density gives the people who can reach the point on foot.
Formula: walk distance = speed × time; radius = distance ÷ detour factor; area = π r²; people = area × density
Worked examples
| Inputs | Straight-line radius | Note |
|---|---|---|
| 15 minutes at 4.8 km/h, detour 1.3, 40/ha | 923 m | 923 m; 268 ha; about 10,700 people |
| An older person at 3.5 km/h | 673 m | 673 m |
| Cycling 15 minutes at 15 km/h | 2,885 m | 2.9 km; 2,600 ha |
FAQFrequently asked questions
What is the 15-minute city?
The idea that daily needs — shops, school, a park, a doctor, transit — should be within a 15-minute walk or cycle of home. At 4.8 km/h through real streets that is a circle of about 900 m radius and 250 hectares, which needs roughly 40 people per hectare to support a local centre.
What detour factor should I use?
Ratio of the real walking distance to the straight line: about 1.2–1.3 in a fine grid, 1.4–1.6 in a loop-and-cul-de-sac suburb, and 2 or more where a river, railway or freeway blocks the way. Network analysis in GIS gives the exact catchment.
Why do speeds differ?
Average adults walk about 1.3–1.4 m/s; older people, children and people with prams or shopping about 1 m/s, which cuts the radius by a quarter. Design for the slower speed where the catchment matters.
What about cycling?
The same arithmetic at 15 km/h: 15 minutes reaches nearly 3 km, ten times the area. Enter the cycling speed to see it.
Where these figures come from
- UN-Habitat — Urban Indicators Guidelines — density, green space and public space benchmarks
- World Health Organization — Urban green spaces — the 9 m² per person minimum
- ITE — Parking Generation Manual — parking demand rates by land use
- Australian Bureau of Statistics — Regional population — Australia's national statistics agency
Last checked: September 2026. Default per-capita rates are mid-range figures from national statistical agencies and utility reports; every one is an input you should replace with the local figure.