Urban Growth Projection Calculator
Where a city's population will be in 10, 20 and 30 years at a growth rate — and how much new dwellings and land that needs at a chosen density, split between infill and greenfield.
Population compounds at the growth rate.
How the urban growth projection calculator works
Population compounds at the growth rate. New dwellings are the added population divided by household size; land is dwellings divided by the density chosen for new development.
The infill share is the policy lever. A city that puts 70% of growth into existing suburbs needs a third of the greenfield land of one that sprawls — the difference is usually the whole argument of a metropolitan plan.
Formula: population(t) = P × (1+g)^t; land = new dwellings × (1 − infill) / density
Worked examples
| Inputs | Population at the horizon | Note |
|---|---|---|
| 850,000 at 1.8% for 30 years | 1,451,618 | about 1.45 million |
| More infill | 1,451,618 | half the greenfield land |
| Denser greenfield | 1,451,618 | much less land |
FAQFrequently asked questions
How fast do cities grow?
One to two per cent a year for growing developed-world cities; three or more in fast-growing regions. Small differences compound enormously over thirty years.
What is infill?
Growth within the existing urban area — apartments, townhouses and subdivided lots — rather than on new land at the edge.
What infill share do plans target?
Sixty to seventy per cent is common in metropolitan strategies. Achieving it is harder than targeting it.
What density should greenfield be?
Fifteen to twenty-five dwellings per hectare for a suburb that can support a bus; below twelve is the car-dependent pattern most plans now try to avoid.
Why does the land figure matter?
Because greenfield land needs roads, pipes, schools and buses that infill largely inherits. Every square kilometer at the edge is a permanent servicing cost.
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
- US Census Bureau — Population and housing — the US 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.