Scale Calculator

This calculator works with scale ratios of the 1:N kind used on models, kits and maps. It converts a real size down to the size on the model, converts a measurement on the model back to real life, works out the ratio from a matching pair of measurements, and re-scales a size from one ratio to another. The two sides can be given in different units, so a real length in metres and a model length in millimetres compare directly. Ratios that match a common scale are named in the result, and one that does not is reported with the closest named scale and what the same object would measure there.