How are distances calculated?FORUMS HOME SEARCH FORUMS

Hello,

I searched the forums but did not find an answer so here goes.

I've been testing measuring distances from both wheel diameter and GPS.

I apparently got the wheel circumference right as the difference in distances between wheel and GPS for a 103 km ride was but 500 meters.

Whatever. I imported my last three "GPS-rides" from this week to Plotaroute.

In Plotaroute, two of them show distances identical down to 2 decimals to what I have in the Roam, one of them differs slightly.

The distances for the rides that show identical distances in Roam and Plotaroute were 51 and 63 kilometers, the one that differed was 103 km. It's logged as 103.39 in the Roam and shows 104.47 in Plotaroute, saved.

That got me wondering about how "mapping distances companies" such as yours calculate distances when creating a route from scratch in Plotaroute.

Is it by using GPS data or something else?

Regards

Online route planning services like ours generally calculate distances between points on the map using a distance formula based on latitude and longitide coordinates of the points plotted.

Thanks. My laymen observations would thus indicate that GPS data for short rides are very accurate?