How long is the Nordic coast?
Norway's coastline is somewhere between 2,500 km and 100,000 km depending on who you ask. That's not a mistake — it's the coastline paradox. The shorter your ruler, the more fjords, skerries and inlets you catch, and the longer the coast becomes.
What you are seeing
A ruler that shrinks
Each step of the slider simplifies the coastline using the Douglas–Peucker algorithm with a different tolerance — effectively walking a ruler of that length along the coast. Lengths are measured geodesically on the WGS84 ellipsoid for accuracy at high latitudes.
Why it matters
Fractals in the fjords
A coastline has no single “true” length. Norway and Iceland — heavily indented and volcanic — grow much faster as detail is added than Denmark's smooth shores. The straight line on the Richardson plot is the signature of a self-similar fractal: the world Lewis Fry Richardson stumbled on in 1951.
Coastline data: © OpenStreetMap contributors (ODbL), via osmdata.openstreetmap.de. Country polygons: Natural Earth. Base map: © CARTO, © OpenStreetMap contributors.