PERF (Performance Equivalency Rating Formula) implements a method for scoring road cycling performances on climbs for ranking and comparison purposes. See scheibo.github.io/perf for more details.
$ go install github.com/scheibo/perf
$ ./perf -t=18m00s -d=4809 -gr=8.12 -h 303
18:00 (4.81 km @ 8.12%) = 508.09
The generated GoDoc can be viewed at godoc.org/github.com/scheibo/perf.