This training pace calculator turns one recent race into five training paces: easy, marathon, threshold (tempo), interval and repetition. Enter the race distance and your time, and it shows your VDOT and each pace per mile or per kilometer, with interval and repetition paces per 400 m as well.
The paces come from VDOT, Jack Daniels and Jimmy Gilbert's estimate of VO2 max from a race result. Easy, threshold and interval paces are the speeds whose oxygen cost is a set share of your VDOT: 60–67% for easy, 88% for threshold and 97.5% for interval. Marathon pace is your predicted marathon race pace, and repetition pace your predicted mile race pace.
A 20:00 5K is a VDOT of 49.8. Its paces per mile are easy 8:33 to 9:21, marathon 7:18, threshold 6:52, interval 6:19 (1:34 per 400 m) and repetition 5:51 (1:27 per 400 m). Per kilometer they are easy 5:19 to 5:48, marathon 4:32, threshold 4:16, interval 3:56 and repetition 3:38.
Easy pace is for base and recovery runs, marathon pace for marathon-pace runs, threshold pace for tempo runs and cruise intervals, interval pace for 3–5 minute repeats, and repetition pace for short fast repeats with full recovery.
These paces are estimates; individual results vary. To see the VDOT number itself, or estimate VO2 max another way, use the VO2 max calculator; to turn your VDOT into goal times at other distances, use the race predictor.