Population Density Calculator
Calculates how many people live per unit area for a given region, using total population and land area. Used by urban planners, policymakers, demographers, and students comparing regions worldwide.
About this calculator
Population density measures how concentrated people are within a geographic area. The formula is: Density = Population / Area (in km² or mi²). When the area is entered in different units, a conversion factor (areaUnit) normalizes it to the base unit before dividing. For context, an area of 1 square mile = 2.59 km². If an urban population percentage is provided, urban density = (urbanPercent/100) × Population / Area, allowing comparison of city cores versus rural surroundings. Annual population growth can be projected using: P(t) = P₀ × (1 + r/100)^t, where r is the growth rate and t is years ahead. Density figures are foundational for resource allocation, housing planning, and infrastructure investment decisions.
How to use
Calculate the population density of Bangladesh: population = 170,000,000 people, area = 147,570 km² (select km² as the unit, so areaUnit = 1). Density = 170,000,000 / (147,570 × 1) ≈ 1,152 people/km². If 39% live in urban areas, urban population = 0.39 × 170,000,000 = 66,300,000. With an annual growth rate of 1.0%, after 10 years: P = 170,000,000 × (1.01)^10 ≈ 187,800,000 people. Re-dividing by 147,570 km² gives a projected density of about 1,273 people/km².
Frequently asked questions
What is a good or high population density, and how do countries compare?
Population density varies enormously across the world. Monaco is the most densely populated country at roughly 26,000 people/km², followed by Singapore at about 8,000/km². Large countries like Canada or Australia average under 5 people/km². A city is generally considered dense above 1,000 people/km², while rural areas typically fall below 50 people/km². There is no universally 'good' density — what matters is whether infrastructure (water, transport, housing) matches the population load.
What is the difference between population density and urban density?
Overall population density divides a region's total population by its total land area, including forests, deserts, and farmland. Urban density focuses only on the built-up, inhabited portion of that area and is always higher. For example, Egypt's national density is about 104 people/km², but nearly 95% of Egyptians live along the Nile Delta, giving that corridor an effective density exceeding 1,500 people/km². Urban density is more meaningful for city planning and service delivery, while national density is useful for broad demographic comparisons.
How does annual population growth rate affect future population density?
Population grows exponentially when a constant percentage rate is applied each year, following P(t) = P₀ × (1 + r/100)^t. Even a modest 1% annual growth rate doubles a population in about 70 years (the rule of 70). Since land area is fixed, density increases proportionally with population. A region with 500 people/km² and 2% annual growth will reach roughly 610 people/km² in just 10 years. This compounding effect is why planners project density decades ahead when designing infrastructure, schools, and water systems.