Work out map area from scale instantly with clear inputs, formula shown and shareable results.
Areas scale with the square of the linear scale, so a 1:50,000 map multiplies areas by 2.5 billion. Forty-five square centimetres on such a map is 11.25 square kilometres, or 1125 hectares. Forgetting to square the scale factor is one of the commonest mistakes in map measurement.
Area scaling
ground area = map area x (scale denominator)^2
Unit conversion
1 km2 = 100 hectares = 1,000,000 m2
Because area has two length dimensions. Halving the scale quarters the represented area, not halves it.
Within a few percent for regular shapes, worse for convoluted boundaries where the map itself generalises the outline.