Bigger dogs age faster than cats and smaller dogs:

	Adult size in pounds
Age 0-20 21-50 51-90 >90 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 36 38 40 42 40 42 45 49 44 47 50 56 48 51 55 64 52 56 61 71 56 60 66 78 60 65 72 86 64 69 77 93 68 74 82 101 72 78 88 108 76 83 93 115 80 87 99 123 84 92 104   88 96 109 Adult 92 101 115 Senior 96 105 120 Geriatric
Relative age of your pet in "human years"

chart from informational handout, "Is your pet a senior citizen?"
©1999 IDEXX Laboratories, Inc.