How to choose a map scale
The scale decides what you see and what you do not. This guide explains how to read it, how to work out how much ground fits on your paper and which scale suits each kind of map.
What 1:25,000 means
Scale is the ratio between a distance on paper and the same distance on the ground. 1:25,000 means one centimetre on the map is 25,000 centimetres in reality, that is, 250 metres.
There is a trick to turn it into something you can grasp at a glance: drop two zeros and you get the metres in one centimetre. At 1:10,000, one centimetre is 100 metres; at 1:50,000, 500 metres; at 1:5,000, 50 metres.
People call a scale “large” when the bottom number is small (1:5,000) and “small” when it is big (1:100,000). It sounds backwards, which is why it confuses: a large scale shows little ground in great detail; a small one, a lot of ground in little detail.
How much ground fits on your paper
The ground that fits is simply the usable paper size multiplied by the scale. A4 is 210 × 297 mm; with a one-centimetre margin on each side you have 190 × 277 mm of drawing. At 1:25,000 that is about 4.8 × 6.9 km of ground.
A 30 cm square with a one-centimetre margin leaves 280 mm of drawing: at 1:15,000 it covers about 4.2 km a side, enough for central Amsterdam or Lisbon; at 1:25,000, about 7 km, a city like Barcelona or Paris from edge to edge.
Note an important consequence: at the same scale, bigger paper gives more ground, not more detail. Going from A4 to A2 without changing the scale shows four times the area, but every street is the same size as before. To make things bigger you have to bring the scale closer.
In PlotMyMap you choose paper and scale first, and the site draws on the explorer the exact frame of ground that will fit. Then you just move it wherever you want.
Working out the scale you need
Often you know what you want to show, not the scale. Then work backwards: measure (on any online map) how long the area is along its longest side, and divide by the usable paper length along that same side.
An example: you want a city's old town, roughly 1.5 km from end to end, on a 30 cm square. That is 1,500,000 mm of ground over 280 mm of paper: 1:5,357. Round towards the next scale so there is some air around it, say 1:6,000.
Rounding a little towards “more ground” almost always looks better than fitting to the millimetre: a map breathes when its subject does not touch the edges.
Old towns and small towns: 1:3,000 to 1:8,000
At these scales every building stands out and can be drawn with its outline and hatching, narrow streets have room to show, and the names of squares and monuments fit.
This is the scale for walled towns and places with a shape: the Cité of Carcassonne at 1:3,500, the star of Naarden at 1:5,000 or the nine sides of Palmanova at 1:7,000. If the charm of the place is its shape, this is the range to show it off.
The limit is ground: a 30 cm square at 1:5,000 only holds 1.4 km. For a whole city you have to zoom out.
A whole city: 1:10,000 to 1:30,000
Between 1:10,000 and 1:15,000 you fit a large village or a city centre with its neighbourhoods: Cadaqués at 1:10,000, Amsterdam and Lisbon at 1:15,000. Streets are still drawn one by one and buildings still show, though very small.
From 1:18,000 to 1:30,000 a whole capital fits: Venice at 1:18,000, Barcelona and Paris at 1:25,000, Washington at 1:30,000. Here a building is half a millimetre on paper and drawing them one by one no longer helps: the map turns into noise. So PlotMyMap changes register and draws the city as blocks, each one hatched whole, and hides minor streets. It always does so from 1:30,000 and, in very dense cities, from 1:18,000.
If your city is too big for the paper, do not keep zooming out: pick a larger paper or keep the most recognisable part (the centre, the coast, the river).
Mountains and hiking: 1:10,000 to 1:50,000
On a topographic map the scale also sets the spacing of contour lines. At 1:10,000 they come every 10 m and you can read every wrinkle of the ground; at 1:25,000, the classic hiking scale, every 20 m; at 1:50,000, every 50 m.
1:25,000 is almost always the best starting point for a day route: an A4 holds a valley or a small massif, and paths, springs and summits read without a magnifier. The Potes example is at 1:10,000 and the Picos de Europa one at 1:25,000.
From 1:50,000 the map becomes regional: a good souvenir of a long trek or a whole range, but less useful for following a particular trail.
Common mistakes
Zooming out too far so “everything fits”. A 40 km map on A4 shows many places and none of them well. Better to crop to what matters.
Zooming in too far on a poster. A 50 × 70 at 1:3,000 only holds 1.5 by 2 km: if the area has little shape, you get a mesh of buildings with no landmark. On a large poster, a whole-city scale usually looks better.
Printing “fit to page”. If your print dialog shrinks the map to fit the sheet, the scale is no longer the one you asked for. Always print at 100 %, actual size.
The scale of a PlotMyMap map is exact on the paper you chose: you can check it with a ruler and with the scale bar on the map itself.
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