How this site measures a route

Every number on this site can be traced to a line on the ground, and every page tells you how much that line has been trusted. This is the full story of where the data comes from, including the parts that make our numbers disagree with the guidebook in your kitchen.

Mapped lines

A route starts as a line computed from real OpenStreetMap footpaths — the same paths that exist on the ground, mapped by people who walk them. Where a routing engine refuses ground that runners actually use (it declined the Zennor boulder field, which is fair comment), we trace the South West Coast Path itself from OpenStreetMap instead. Elevation comes from open elevation models sampled every fifty metres along the line, then filtered: a median pass to remove the one-sample spikes these models throw beside water, and a threshold so that metres of climb only count once a real rise has happened.

Distance and climb on a route page are derived from that line, not typed in. If the geometry changes, the numbers change with it. Nothing can quietly drift.

Recorded lines

When a route gets run, the mapped line is replaced by the GPS track of the run itself, elevation included, and the page's status flips to field checked with the date shown. The downloadable GPX is resampled from that recording with timestamps and device data stripped out. You get the line; the heart-rate stays private.

Why our climb figures read low

Walking guides for the coast path often quote gain figures a third higher than ours. Neither is lying. Elevation models smooth the landscape into 25-metre cells, which flattens the sharpest notches — a stream cut you drop into and climb out of inside eighty metres barely registers. Our filtering then deliberately refuses to count noise as climbing. The result underestimates routes with constant short violence, and says so on their pages: Port Isaac to Port Quin is the honest worst case, a route whose profile underplays how sharp every dip really is.

A recorded run with a barometric watch sits between the two, and that is one reason recorded lines replace mapped ones the moment they exist.

What the labels promise

• Desk-researched — real geography from real map data; nobody from this site has run it yet, and the page says so.
• Field checked — run on the ground, line and profile from the recording, date shown.
• Verified — field checked plus the practical details (parking, buses, access) confirmed per our checklist.

If a page hasn't earned a word, it doesn't use it. That is the entire editorial policy, and it applies to the race calendar too — dates there are provisional until checked against the organiser, because a stale race date can cost someone a booked cottage.