Land Use Calculator

Land area comes in a confusing array of units. In the US, farmland is measured in acres. Science and most of the world use hectares. Satellite imagery and urban planning often use square kilometers. Real estate uses square feet. Converting between them is a constant chore.

Key conversions:

• 1 hectare = 2.471 acres = 10,000 square meters
• 1 acre = 0.4047 hectares = 43,560 square feet
• 1 square mile = 640 acres = 2.59 square kilometers
• 1 square kilometer = 100 hectares = 247.1 acres

To put areas in context: a standard American football field (including end zones) is about 1.32 acres. Manhattan island is roughly 14,600 acres or 59 square kilometers. Central Park is 843 acres. The Amazon rainforest is about 550 million hectares.

Agricultural productivity estimates are rough global averages. Actual yields vary enormously with soil quality, water availability, climate, and farming practices. US Midwest corn belt averages around 11 tonnes/hectare — roughly twice the global average. Wheat yields in the UK approach 8-9 t/ha; global average is closer to 3.5 t/ha.

Forest carbon sequestration averages 2-5 tonnes of CO2 per hectare per year for temperate mixed forests, with tropical forests sequestering more but also emitting more from decomposition. Net sequestration figures are what matter, and these vary by forest age and type.

Solar farms typically produce 150-200 MWh per hectare per year in good-insolation regions, rising to 250+ MWh in desert areas. That is enough to power about 40-60 average US homes per hectare, year-round.