Knowing how to read a map is vital if you are to enjoy adventures in the outdoors to the maximum. After all, there’s no point having the best hiking boots if your feet don’t know in which direction to take them.
Let’s deal with the elephant in the room head-on. Why learn navigation at all when modern tech makes things so easy? Recent advances in GPS and phone technology have led to a revolution in digital mapping. Apps like Google Maps are now an everyday part of life and navigation apps like komoot, Outdooractive, AllTrails and Gaia GPS are giving us new, innovative and convenient ways to navigate in the outdoors.
Whilst these are admittedly fantastic tools, they rely heavily on your phone, its battery and the signal it receives. Even on the world’s most popular trails, if the weather turns, you are caught in a whiteout and your battery dies because of the cold, you’ll wish you knew how to read a map and how to use a compass.
In short, knowing how to read a map is more than just useful — it can be a potentially life-saving skill. Here’s our simple guide to getting started.
Locating the right map
A one-size-fits-all answer to the question of how to read a map is not easy, as there are many different types 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, or the 1:24,000 maps produced by the United States Geological Survey in America.
At first glance, it can be overwhelming trying to work out what the various lines and symbols mean, as there is an awful lot of information to take in and you might wonder if you’ll ever learn how to read a map. However, take a breath, consult the legend (sometimes called the key) and you will discover what the colored icons, symbols and lines represent.
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 features, 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. Generally, you can get hold of individual maps that cover particular areas. National Parks and popular hiking regions are usually extremely well catered for.
In Britain, the most recognised topographic maps are Ordnance Survey (OS) Maps. Also popular are Harvey maps, which are specifically designed with hiking and mountaineering in mind. The United States Geological Survey (USGS) is the American equivalent of Britain’s Ordnance Survey, while National Geographic Maps are also very popular.
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 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. The main mapmakers mentioned above all have digital platforms and they rank among the best navigational apps available.
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 Britain’s 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 in Britain generally use 1:25,000 maps, whilst the most used scale for USGS maps is a similar 1:24,000. Both of these allow hikers to see in detail geographical features such as rocky outcrops and markings, helping them to orientate where they are. This kind of detail is also ideal if you plan to go night walking.
Cyclists, backpackers, thru-hikers and expedition runners – those who are planning on 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.
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. The key as to how to read a map is exactly that: a key. Also known as a legend, the key sits in the corner of the map for you to refer to and tells you what the different symbols mean so that you know what you are looking at. Of course, different map brands in different countries have different colour codes and symbols, so it's good to familiarise yourself with the brand you are using.
Arguably most important to many map readers are the lines that indicate a public right of way or footpath and trails that you can both walk and ride (on a horse or a bicycle). 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 – public toilet icons, little tent symbols signifying camping areas, and footbridge icons, denoting where you can cross rivers and streams – to the very useful: picnic spots, good viewing points and places to eat and drink. Brits often scour their OS Maps looking for PH, which means Public House (pub), for when they 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 different varieties of woodland. Pine plantations may be represented by icons looking somewhat Christmassy, whilst mixed woodland might be represented by a bushier, broccoli-esque icon. Once you know these details, you can often work out if you are where you think you are by the flora around you.
Understanding contour lines
Understanding how to read a map when you're in the mountains has a lot to do with contour lines.
Here's a bit of history for you. In 1774, a Scottish mountain called Schiehallion was the subject of a ground-breaking experiment to determine the mass of the Earth by Astronomer Royal, Nevil Maskelyne. This was due to its almost symmetrical shape and isolation. The experiment was based around the hypothesis that Schiehallion’s known mass would have an observable gravitational attraction on objects and that this phenomena could be measured. The data was then used, incredibly, to calculate the mass of the Earth for the first time. The calculation, although not perfect, was pretty accurate.
Maskelyne gave the task of calculating Schiehallion's mass to a man named Charles Hutton. Hutton did this by triangulating its height at various points across the mountain's area and joining the dots. The result of this study was the birth of contour lines.
Contour lines are 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. They can also help you plan where you are going to pitch your tent for the night. Even the best tents don't cope well on a slope.
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
You can't learn how to read a map, without a grasp of orientation. 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.
Using a compass to take a bearing is a more advanced technique.
National grid lines
A good map will always have grid lines, regardless of brand or region. In Britain, 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.
As a child at school, you'll have learnt all about co-ordinates and grid references, finding treasure on treasure maps or playing Battleships. In fact, you'll find that kids love maps. Teaching them your map reading skills is a great way to get them involved and keep them entertained on your family hike...
Any map you'll use in the outdoors is covered in faint lines, which make up a grid. Each grid square will measure a set area, 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 square on a map, and six-figure grid references (when you use the smaller incremental 1-10 markings between the numbers) identify a smaller 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.
If you are also using digital mapping on your phone, it's a good idea to bring a portable charger, so that if you're battery dies, you can charge it back up. Just don't forget the cable!
Hiking in Britain: should you use Ordnance Survey or Harvey?
The two mainstays for hikers in Britain are Ordnance Survey (OS) and Harvey.
Ordnance Survey are the national mapping agency of Great Britain and are very much pioneers in the field. It was Ordnance Survey who built triangulation pillars on high ground across the nation. This was in order to calculate the height of the land at various points. Their Explorer series is immensely popular with those heading into the British countryside. The usual scale for OS Maps are 1:25,000 and 1:50,000, though larger scale maps are available.
However, OS Maps are designed for general use. A popular alternative to Ordnance Survey is Harvey, which are designed specifically with hikers and mountaineers in mind. They are waterproof as standard and show the intricacies of terrain in more detail than OS Maps. Maps are available at 1:25,000, 1:30,000 and 1:40,000 scale.
So if you’re off to do the best walks in the Lake District, an OS map should suit you just fine. However, if you are traversing more technical ground, like the rocky terrain of the Isle of Skye’s Cuillin Munros, then Harvey could be the best bet.
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. In fact, a region's geology can affect your compass needle. The gabbro rock of the Isle of Skye in Scotland is notorious for throwing your compass completely out.
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.
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.
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