Area unit converter

Essential in property and farming, where square metres, hectares, acres and square feet coexist depending on the country.

Every unit is referenced to the square metre. Remember that area factors are the square of length factors: a foot is 0.3048 m, but a square foot is 0.0929 m².

The factor is squared

A metre is a hundred centimetres, but a square metre is ten thousand square centimetres. Moving from length to area, the conversion factor multiplies by itself. It is the number one source of budgeting errors on site, and an order-of-magnitude mistake on a materials invoice.

The acre comes from what an ox could plough in a day

It is 4,046.86 square metres, a figure with no decimal logic because it descends from a medieval agricultural measure: the area a man with a team of oxen could plough in a day. The hectare, by contrast, is a clean metric invention: ten thousand square metres, a hundred metres square.

Traditional local measures

In Spain, Latin America and other countries, traditional agrarian measures survive whose value changes by province or even by municipality. When buying rural land, always ask for the registered area in square metres rather than the traditional one.

Registered and actual area

They may not match. The cadastral figure is what appears in public records and the actual is what is measured on the ground. In a sale, the difference between them can be grounds for negotiation or dispute.