Hectare — Definition, Formula & Examples

A hectare is a metric unit of area equal to 10,000 square meters, commonly used to measure large areas of land such as farms, parks, and forests.

The hectare (symbol: ha) is a non-SI metric unit of area defined as exactly $10^4$ square meters, equivalent to a square with side length 100 meters. One hectare equals approximately 2.471 acres.

Key Formula

1 \text{ ha} = 10{,}000 \text{ m}^2 = 0.01 \text{ km}^2

Where:

$\text{ha}$ = hectare, the unit of area
$\text{m}^2$ = square meters
$\text{km}^2$ = square kilometers

Worked Example

Problem: A rectangular farm measures 400 m by 750 m. What is its area in hectares?

Find the area in square meters: Multiply length by width.

400 \times 750 = 300{,}000 \text{ m}^2

Convert to hectares: Divide by 10,000 since 1 ha = 10,000 m².

\frac{300{,}000}{10{,}000} = 30 \text{ ha}

Answer: The farm has an area of 30 hectares.

Why It Matters

Hectares appear constantly in geography, agriculture, and environmental science when describing land areas. Understanding this unit helps you interpret news about deforestation, farm sizes, and urban development, and it is tested in middle-school measurement problems involving metric unit conversions.

Common Mistakes

Mistake: Confusing hectares with square kilometers and dividing by 1,000 instead of 100.

Correction: There are 100 hectares in 1 km², not 1,000. Since 1 km = 1,000 m, we get 1 km² = 1,000,000 m², and dividing by 10,000 m²/ha gives 100 ha per km².