Find your age, then look beneath the desired percentage of HR Max to determine your training heart rate in beats per 15 seconds.

Table of Aerobic Target Training Zones

AGE RANGE	50%	55%	60%	65%	70%	75%	80%	85%	90%
15 - 20	25	28	30	33	36	38	41	43	46
21 - 25	25	27	30	32	35	37	39	42	44
26 - 30	24	27	29	31	34	36	38	41	43
31 - 35	23	26	28	30	33	35	37	40	42
36 - 40	23	25	27	30	32	34	36	39	41
41 - 45	22	24	27	29	31	33	35	38	40
46 - 50	22	24	26	28	30	32	34	37	39
51 - 55	21	23	25	27	29	31	33	36	38
56 - 60	20	22	24	26	28	30	32	34	37
61 - 65	19	21	23	25	27	29	31	33	35

Tips for using the table of target training zones...