We measure each course from recorded runs. This page states the method and the numbers.
Climb is the total height that a course goes up.
| Course | Ours | Published | Source |
|---|---|---|---|
| Boston Marathon | 821 ft | 815 ft | B.A.A., surveyed |
| Honolulu Marathon | 456 ft | 457 ft | FindMyMarathon |
| Rock 'n' Roll San Diego Marathon | 828 ft | 813 ft | FindMyMarathon |
For San Diego we also compared the descent, the high point and the net change. All of them agree to approximately 2%.
The line. We average many recorded runs of the course into one line. Then we check that the line covers the same ground as the runs. A correct distance is not enough.
Elevation. We take the height from USGS 3DEP, the public elevation model of the United States. We sample it every 10 meters along the line.
Climb. We count a rise only when it goes more than 10 feet above the last low point. A barometric altimeter counts in the same way. A sum of every small change would be too large.
The check. Some recorded runs also hold a barometric height record. Before we publish a course, we compare the shape of that record with the shape of our model. If the two do not agree, we do not use the model.
Bridges. An elevation model shows the bare ground, so at a bridge it shows the water and not the road. We rebuild the road only where the course crosses water on the map. If we are not sure, we keep the dip.
Refusals. Sometimes no instrument passes the check. Then we show a figure from a different source, or we show no figure. The Houston page shows FindMyMarathon’s 217 ft.
The chart. Every elevation chart uses the same minimum vertical range. A flat course therefore looks flat.
We measured these figures in August 2026. They change only when we measure a course again. Each course page names the device that recorded the run.