Find ground distance, map millimetres, or the 1:n scale when you have the other two.
| Map mm | – |
| Ground m | – |
| Scale n | – |
Use this for walking a paper map or checking that a printed plan really is 1:25 000. Fill the two known boxes and pick Find for the missing piece.
Ground metres = (map mm / 1000) × n. So on 1:25 000, 1 mm on paper is 25 m on the ground. This is a representative fraction, not a graphic bar scale drawn on the sheet.
Map length (mm): How long the feature is on the paper, in millimetres.
Ground length (m): How long it is in the real world, in metres.
Scale n (1:n): The n in 1:n; 25000 means 1:25 000.
Find: What you do not know yet: ground length, map length, or scale.
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