Map and compass: the basics

A phone with a mapping app is a fine way to follow a route, until the battery dies, the screen is soaked or your hands are too cold to use it. A paper map and a compass work in all three, and reading them is a skill worth an afternoon.

Which map

• OS Explorer (1:25,000): 4 cm to the kilometre, with walls, fences and access land. The usual choice for walking in England and Wales.
• OS Landranger (1:50,000): 2 cm to the kilometre. Less detail but clearer on big, open hills, so popular in the Highlands.
• Harvey maps: made for walkers, on waterproof paper, covering the main mountain areas.

Reading the ground from the map

• Contours are lines of equal height. Close together means steep; far apart means gentle. Rings closing inwards are a summit; V shapes pointing uphill are valleys and streams.
• Grid squares are 1 km across on both scales, which makes distance easy to judge.
• A six-figure grid reference pins a spot to within 100 m: read along the bottom first, then up the side. Try the grid reference converter.

Set the map

Turn the map until what's on it lines up with what's around you: the loch on your left on the map and on the ground. With the compass, turn the map until its north lines run the same way as the red end of the needle. Walk with the map set and your thumb on where you are.

Walk on a bearing, in three steps

1. Lay the compass edge on the map from where you are to where you want to go, direction arrow pointing to your target.
2. Turn the dial until its lines match the map's north-south grid lines, with the dial's N to the top of the map.
3. Take the compass off the map, hold it flat in front of you and turn your whole body until the red needle sits in the red outline. Walk where the direction arrow points.

Grid north and magnetic north differ slightly. In Britain the difference is small at present and changes with place and year: the margin of your map gives the figure.

Make it easy for yourself

• Handrails: follow a wall, stream or ridge that runs your way.
• Catching features: note something beyond your target (a path, a steepening) that tells you you've gone too far.
• Timing: at a steady walk you cover about 1 km in 12 to 15 minutes on good ground. Checking the clock tells you roughly where you are.

General guidance from the TRXO team, last read through on 6 Nov 2026. It is no substitute for training or for your own judgement on the day.