| Trail | Official | Measured | Difference |
|---|---|---|---|
| Kepler Track | 37 mi | 32.1 mi | -13% |
| Foothills Trail | 77 mi | 86.6 mi | +12% |
| Lost Coast Trail | 25 mi | 27.8 mi | +11% |
| Loowit Trail | 30 mi | 26.6 mi | -11% |
| GR20 | 112 mi | 123 mi | +10% |
| Long Trail | 272 mi | 247.2 mi | -9% |
| Camino Francés – Stage 1 | 93 mi | 101.8 mi | +9% |
| Wonderland Trail | 93 mi | 85.4 mi | -8% |
| Rae Lakes Loop | 41 mi | 37.6 mi | -8% |
| The Narrows | 16 mi | 15 mi | -6% |
| West Highland Way | 96 mi | 101.5 mi | +6% |
| Ouachita National Recreation Trail | 223 mi | 213 mi | -4% |
| Rockwall Trail | 34 mi | 32.8 mi | -4% |
| John Muir Trail | 211 mi | 207 mi | -2% |
| Timberline Trail | 40 mi | 39.7 mi | -1% |
| Trans-Catalina Trail | 38.5 mi | 38.1 mi | -1% |
| Milford Track | 33 mi | 33.3 mi | +1% |
| Salkantay Trek | 46 mi | 46.3 mi | +1% |
| Tahoe Rim Trail | 165 mi | 165.8 mi | 0% |
Official distances are from park services and trail authorities (per-trail sources in our dataset). Measured distances are computed from each trail's real OpenStreetMap geometry (© OpenStreetMap contributors, ODbL). Trails whose available geometry doesn't yet cover the full route are excluded here, so every comparison is like-for-like.
Why the sign and your GPS never quite agree
Two honest measurements of the same trail routinely differ by a few percent, and neither is "wrong." GPS wanders — in canyons, under tree cover, and on switchbacks it records extra zig-zag, so a GPS track usually reads a little long. Official signage, meanwhile, is often rounded to a tidy number, measured off a map rather than the walked tread, and re-surveyed only every several years. So the "true" distance sits somewhere between them.
The useful takeaway for planning: don't treat any single mileage as gospel. A trail advertised at 40 miles could realistically walk anywhere from 38 to 44 — which, spread across a multi-day trip, is a whole extra hour or two of hiking some days. That's why planning by time and effort per day beats planning by raw miles.
Plan It For Real
Plan by time and effort, not just miles
Ridgefold measures your route from real trail geometry and breaks it into days — per-day miles, elevation, and hiking time between each campsite — so a fuzzy trail-sign number never leaves you hiking into the dark.
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Questions
Are backpacking trail distances accurate?
Mostly, but rarely exact. Across 19 popular trails, GPS-measured length differed from the official signed distance by about 6% on average, with 15 of 19 within 10%. Trail signs are measured infrequently and GPS tracks vary with terrain, so a small gap is normal.
Why do my GPS and the trail sign disagree on distance?
GPS wanders in canyons and tree cover (which adds distance), while official signage is often rounded, measured years apart, or taken from a map rather than the walked path. Neither is perfectly "true" — expect them to differ by a few percent.
Do trails tend to be longer or shorter than advertised?
It goes both ways. Of 19 trails measured, 8 came out longer than advertised and 11 came out shorter — there's no consistent bias, which is itself a sign that both figures are close.