The Ordnance Survey is planning to adjust the Victorian-era formula for calculating walking route times as ramblers are failing to keep up pace.
The national mapping agency will this August be inviting hikers to track their rambles via its app to work out how fast they are actually walking and taking breaks for.
The anonymised data will then be used to tailor how the OS calculates route times on its app, which currently uses the standard Naismith’s Rule – a system devised by an elite Victorian climber in 1892.
However, its creator, Sir William Naismith, was an ultra-fit 36-year-old when he designed the method, who had pioneered many difficult winter climbs in the highlands.
The OS is concerned that the three-miles an hour pace he determined for hiking on flat terrain is too rapid for less nimble 21st century ambler and causing them miscalculate how long their walks will talk.
Tim Newman, the digital project manager at the OS, told the Telegraph: “We want to make sure people aren’t put off as they go for their first walk and it (the app) tells them it will take them two hours when it takes them five.
“At worst it can mean you are left out in the dark, but at best it is a bit demoralising and you might have some moaning kids.”