Sagot :
Answer: Do it yourself
Find your scale. Maps have different scales e.g. for an explorers map 1:25,000.
Measure distance on map say in centimetres.
Use a ruler, string, or almost anything, pencil, fingers, a twig or I like a spare piece of paper.
Place against the scale for a direct reading.
Or calculate distance.
Say you measure 4 cm on the map. Then remember in this case 1:25,000.
so 4x1 or 4 = 4x25,000 = 100,000 cm real or actual distance.
In meters divide by 100 = 100,000/100 = 1,000 metres. (= 4cm on map).
or in kilometres divide again by 1,000 = 1,000/1,000 = 1 Kilometre. (= 4cm on map).
Also a tip just proved: 1:25,000 is the same as 4 cm = 1 Km or 1 cm = 1/4 Km real.
And best for walking a 1:50,000 scale map 2 cm = 1 Km or 1 cm = 1/2 Km real.