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How to read a map: become a navigation expert with our simple guide

How to read a map
Knowing how to read a map is an essential life skill (Image credit: Getty)

Knowing how to read a map is important when spending time in the outdoors. Here’s our guide to how to read a map, orientate yourself and choose the best type of map that suits your needs, so you can become a navigation ace. 

Being able to read a map is an essential life skill if you're discovering new local footpaths or planning future hiking and backpacking escapades. Although phones have GPS and countless navigation apps, it is important not to rely on them entirely as your sole source of navigation. Phone batteries can run out, or you may be stuck somewhere remote with no phone or satellite signal. In these scenarios being able to read a map is more than just useful – in some areas, it can be a life-saving skill. Here’s a simple guide to getting started.

Locating the right map

There are many different types of maps out there. For hiking and other outdoor adventures, you will need a proper topographical map, produced by cartographers to a clearly identified scale, such as the excellent 1:25,000 and 1:50,000 maps produced by Ordnance Survey in Britain. (More on what those scales mean below.)

At first glance, it can be overwhelming trying to work out what such a map shows you, as there is an awful lot of information to take in. However, consult the legend (sometimes called the key) and you will discover what the various icons, symbols and lines represent, including footpaths and riding trails (bridleways). 

Topographical maps show the landscape from above, looking directly down, so it’s useful to imagine how the terrain you’re traversing would look from a bird’s eye view. As well as showing the landscape of an area, maps will often show a number of other features that help us identify where we are, including roads, rivers, buildings, large overhead power lines, trees and lakes.  

Used correctly, a map can allow you to accurately plan a journey, giving a good idea of landmarks and features you will pass along the route, as well as how far you will be traveling. 

It is always worth owning a map if you are likely to be returning to an area over and over again – there’s nothing more exciting than pouring over a paper map in the comfort of your own home, planning a new adventure. Maps can be bought for each region of Britain, with popular areas such as the Peak District requiring OS1 and OS24, while the Lake District has four maps – OL3, OL5, OL6, Ol7. 

Of course, paper maps do eventually become dated, with new roads being built or areas suffering erosion and footpaths falling into the sea. Digital mapping software such as OS Maps allows you to print up-to-date maps to scale and make multiple copies, which is useful for hillwalkers who want flexibility with their plans. It is always advisable to have a copy of a map and compass alongside a digital form of navigation, such as OS Maps/ Viewranger.

A question of scale

When you're learning how to read a map, scale can be one of the hardest things to get your head around. Maps are shown in different scales, for example, 1:25,000 or 1:50,000. A 1:25,000 scale means 1cm on the map equates to 25,000cm on the ground (so 250 meters); 4cm on the map equals 1000 meters (1km) – a distance also represented by one square on the grid that is overlaid on Ordnance Survey maps. (In imperial, that’s 2½ inches to 1 mile.) On a 1:50,000 map, 1cm is 50,000cm in real life, so 1cm equals 500 metres, and 2cm is 1,000 metres (1km).

The larger the map scale (which, somewhat counter-intuitively, means the smaller the number – so a 1:25,000 map depicts the terrain in a larger scale than a 1:50,000 map), the more detail that will be shown. Day walkers, hikers and hillwalkers generally use 1:25,000 maps, which allow them to see in detail geographical features such as rocky outcrops and markings that help them orientate where they are. 

Cyclists, backpackers, thru-hikers and expedition runners – those who are planning covering larger areas over a short period – may use 1:50,000 maps, which show a greater area. People who use maps in winter, when the covering of snow means detailed features are lost and contours and gradients become more important, also often favor the latter. 

It’s quite a subjective choice – pick a scale that is appropriate for what you’re using the map for. For those who plan on covering a wider mountain region, Harvey Maps produce 1:40,000 maps that show a slightly different key, using different colors to denote heights of peaks, which can help make navigation more straightforward.

Symbols and legends

Most maps use symbols, rather than descriptions, to show where things are, and also abbreviations. This is to avoid the map being crowded with writing, making it harder to read. Good maps will have a key, known as a legend, for users to refer to, so you know what you are looking at. 

Arguably most important to many map readers are the lines that indicate a public right of way or footpath – short green dashes – and trails that you can both walk and ride (a horse or a bicycle), which are indicated by long green dashes. Remember, though, just because a path looks clear on a map, it won’t necessarily be obvious on the ground, so keep checking your map to see whether you’re passing the landmarks that indicate you’re on the right track.

Symbols and abbreviations range from the essential – WC in blue writing denotes a public toilet, little tent symbols signify camping areas, and footbridges are identified by the abbreviation FB, denoting where you can cross rivers and stream – to the very useful: an upside-down triangle with crossed legs indicates a picnic spot, good viewing points are indicated by a splayed semicircle of blue dashes and PH means Public House (pub), for when you want to know where the nearest place is to get a beer.

Likewise, knowing the difference between various symbols can be really helpful when navigating through different types of terrain, such as woodland (bushier, broccoli-shaped trees refer to non-coniferous trees, while coniferous trees are represented with a Christmas tree symbol). Once you know these details, you can often work out if you are where you think you are by the flora around you.

Map reading is vital when venturing off into the wilderness

Map reading is vital when venturing off into the wilderness (Image credit: Getty)

Understanding contour lines

Contour lines are orange or brown squiggly lines, with numbers next to them. The lines represent the contours (shape) of the land, and the numbers tell you the height each line is above sea level. The closer together the contour lines are, the steeper the slope. If a contour line is pointing in a ‘v’ shape and they look close together, this will suggest a narrow slope that is steep, also known as a spur. The inverse of this (a clump of lines in a roof, or ‘n’ shape) might signify a decrease in the height – often water features are found here, due to the slope aspect. These are known as re-entrants. 

Whether you’re a basic hill navigator or a seasoned pro, contours are incredibly useful when planning a route, as you can get a good picture of how steep it will be and prepare accordingly. If you are in a relatively flat area and see a clump of orange contour lines ahead, you know to expect some steep hills that require a tough ascent.

On most maps, the interval between contours is usually 5 meters, but in mountainous regions, it may be 10 meters. This can be checked against the legend. Contours can quickly reveal if the area planned will require a longer time to walk around. As a rule of thumb, for every 10 meters of height climbed, it’s worth adding on an additional minute of expected walking time. 

Orientate your map

Orientating the map simply means getting the map to face in the same way as you are looking or walking. A surprisingly common problem when walking with a map is simply getting started in the right direction from the village, train station, car park or trailhead – getting your map orientated will help enormously with this. It’s always worth doublechecking you are on the path you think you are on, and not heading up a dogleg, particularly in popular mountain regions where there are multiple routes. 

Fold the map into a smaller square, covering the area you are walking in, and imagine you are a tiny figure hovering over that area. Look around you, and imagine what you would see if you dropped out of the sky and onto the ground. 

The paper map you are holding is the depiction of what you should be able to see around you. Use a small twig or blade of grass as your ‘pointer’ and try and identify any common features nearby. Hills and woodland can be easy identifiers, as well as church spires and castles. Position the map accordingly, so it is facing the right way, and it’s easier to conceptualize the trail ahead from the information on the map and in front of your eyes. You can also orientate a map with a compass – our how to use a compass guide explains how.

Map and compass

A compass can help orientate a map to your surroundings (Image credit: Getty)

National grid lines

Ordnance Survey maps all have two-letter prefixes. To understand what these mean, picture the UK divided into 100km squares, with each square given two letters. In situations such as where you might need to quote a grid reference, be sure to include the two-letter prefix so that the grid reference corresponds to the correct square. This is particularly important in wider geographical areas that might span several map squares.

Grid references

Ordnance Survey maps are covered in faint blue lines, which make up a grid. Each grid square measures 1km by 1km, and they have associated numbers, running horizontally and vertically along the edges of the map. These numbers are what you use to pinpoint your location on a map. This is useful for giving people directions to a remote camp spot, for example, or in an emergency to relay your location to mountain rescue.

To take a grid reference, remember the useful phrase: ‘along the corridor and up the stairs’. The first numbers you quote are the ones that run along the bottom of the map, from left to right – the ‘Eastings’. The second block of numbers you should quote are the ones read from bottom to top, known as ‘Northings’.

Four-figure grid references identify a single 1km square on an OS map, and six-figure grid references (when you use the smaller incremental 1–10 markings between the numbers) identify a smaller 100m square, which should be sufficient for anyone to locate the spot you’re talking about. 

Latitude and longitude

Latitude and longitude are global addresses, written in numbers so that everyone can use them regardless of where they are. These are the numbers you see when you click on ‘Your Location’ on Google maps, and they give a very accurate reference point to where you are. They are given as coordinates, made from horizontal lines, with the equator referring to 0 latitude, and vertical lines, with the line passing through the prime meridian referring to 0 longitude. It’s worth noting that some international maps don’t use grid references, but use latitude and longitude only. 

Carrying a back-up

Finally, for those who wish to master the art of becoming a navigation pro, get practising and remember to carry a spare form of navigation in case one fails – for those in mountainous regions it’s worth carrying a spare map and compass separate to your main tools. 

Common map-reading mistakes

Hidden or indistinct footpaths
Most maps will show when the footpath or right of way changes. If the green dotted line suddenly appears on one side of a solid black line before switching to the other side, this might mean there is a wall that needs to be crossed, which will either have some kind of signpost or small steps built-in. When walking across areas with multiple paths, keep track of which path you are walking on.

Confusing boundary lines, paths and footpaths
People can often misinterpret a boundary line for a path or footpath or vice versa when looking at a map. Boundary lines are sometimes old drystone walls, or disused fences, or may not exist at all. It’s important to recognize what this looks like so you don’t end up looking for a footpath that doesn’t exist when out on a walk. Check the map legend carefully.

Walking while holding your compass
Walking a few paces sideways can throw your compass off course, even though you are still walking in the right direction. Magnetic interference from mobile phones and electronics can also affect the signal. Also walking whilst holding a compass can distract you from looking out for danger. It’s best to line your compass up with something in the distance and head towards that.

Selecting a moving object to walk towards 
It’s best to be walking towards something in the distance that is not likely to move, such as a distinctive rocky outcrop, a trig point, a significant peak or church spire. In poor visibility, it is easy to mistake a sheep for a rock!

Not taking magnetic variation into account 
Make sure you check for magnetic variation in the area you’re exploring and take it into account when lining up your compass. The magnetic variation will be printed on the map.

Not trusting your compass 
If you think your compass is pointing you in the wrong direction, then start again to work out your direction. Check the compass hasn’t become de-magnetized, which is usually when a compass has been exposed to a battery or a torch. If it says the same direction again, then trust it – usually, it is right, and your sense of direction is wrong.

Top tip
Make sure you look after your maps by putting them in a clear map case, which helps prolong their lifespan and readability. OS Explorer maps are simple paper maps that can be cost-effective, while OS Active maps are slightly more expensive, plastic-coated maps that are water-resistant and can be much tougher and longer-lasting. Harvey maps are also water-resistant and are very lightweight.