OS re-measured Ben Nevis in 2016, and found it to be 1345m tall - one metre more than the last measurement in 1949. Find out more about the tallest mountain in Britain and how to climb it
In 1949 a team of OS surveyors carried 200lbs of equipment up Ben Nevis and its surrounding mountains. Taking multiple readings over 20 days, they waited till night so that the marker lights were visible, and then measured the angles between the peaks to calculate the height of Britain's tallest mountain. They measured the height to a little over 1,344m which has been the 'official' height ever since.
Field Surveyor Angus Hemmings was one of three surveyors who climbed Ben Nevis to take a new measurement using the latest GPS equipment, which is accurate to around 1cm. They found that the height was just a few centimetres higher than the 1949, but with rounding, this increased the official height 1345m.
"What it did do though, was give me a greater sense of respect for the 1949 surveyors. It took the surveyors 20 nights, because they only had three clear nights in that period to get it right. To do the best possible job it had to be run with military precision, everything they did had to be timed to perfection. Their effort and accuracy is remarkable.” - Angus Hemmings, Surveyor
Climbing Britain's Highest Mountain
Ben Nevis demands respect - even in summer. If you are planning on climbing it, you'll need:
The right equipment - sturdy boots and clothing to cope with a variety of weather. Even in summer the summit can be considerably colder than the valley. In winter, snow and ice means crampons and an ice-axe are vital.
A good level of fitness - while the Mountain Trail ('Pony track' or 'Tourist Trail') is relatively easy with no climbing, it's still a steep 17km (just under 11 miles). Experience walking similar distance on rough terrain is advised.
Navigation skills - while the main path is pretty easy to follow, especially in summer, poor visibility is not unusual at any time of the year. Take a map and compass and know how to use them. A GPS or a GPS app would be useful too, but be aware that most phone batteries will not last long enough, so take spares or a portable recharger.
A plan - the easy route takes seven to nine hours, and can take considerably longer in poor conditions. This means at most times of the year you are likely to be doing at least part of it in the dark - it's generally better to start early and plan to get back down while it is still light.
Backup - leave details of your route with family, friend or your accommodation, with when you plan to start, finish and the route you are taking. Don't forget to tell them when you get back safely! See here for a printable route card.
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Routes up Ben Nevis
The Mountain Trail (Pony Track or Tourist Track)
The simplest and most popular route up Ben Nevis. It begins at Achintee on the east side of Glen Nevis about 2 km (1.5 miles) from Fort William town centre. You can also join it from the Glen Nevis Visitor Center car park on the other side of the River Nevis where it can be easily accessed using the footbridge and following the path for to where it joins the Mountain Track.
The route is around 16.5km there and back and will generally take six too nine hours, depending on conditions and your normal walking speed.
For the more experienced walkers, starts at Torlundy North Face car park, a few miles north-east of Fort William on the A82 road, and follow the path alongside the Allt a' Mhuilinn. you can also follow the Mountain Track as far as Lochan Meall an t-Suidhe (halfway lochan) and taking the left fork. You will pass the spectacular North Face cliffs, Castle Ridge, Carn Dearg Buttress and Trident Buttress.
Take the steep ascent of Carn Dearg Meadhonach before an easier slope leads to Carn Mor Dearg and then continues along the breathtaking Carn Mor Dearg Arete before climbing steeply to the summit of Ben Nevis itself.
This one-way route starts from the car park in Glen Nevis at NN 167 691, passes by the ruins Steall.
This is a dramatic route, with a tough, steep climbs followed by a relatively level path. Crossing between Aonach Mor and Carn Mor Dearg is an energy-sapping descent and climb, followed by a relatively flat, but still challenging ridge walk to the peak.
From here you can follow the mountain path and continue to Fort William, or return the way you came. Total distance is about 21.3km, woth tough terrain, so this should also only be tacked by experienced walkers.