A Dog's Age in Human Years

Note: The original "Senior Dogs Project" website uses imperial weights - that is, "Up to 20 lbs", "21-50 lbs", "51-90 lbs" and "Over 90 lbs". I've converted these to metric using 1Kg = 2.204622622lbs and rounded to the nearest integer. Also note that the weights in pounds are rounded to the nearest integer. Please also check out the chart on the next page (refer below).

Age <10Kg 10-25Kg 25-40Kg >40Kg Averages
5 36 37 40 42 39
6 40 42 45 49 44
7 44 47 50 56 49
8 48 51 55 64 55
9 52 56 61 71 60
10 56 60 66 78 65
11 60 65 72 86 71
12 64 69 77 93 76
13 68 74 82 101 81
14 72 78 88 108 87
15 76 83 93 115 92
16 80 87 99 123 97
17 84 92 104 130 102
18 88 96 109 137 108
19 92 101 115 145 113
20 96 105 120 152 118

Age Ranges: Senior <9.5Kg 7 - 13
9.5 - 22.7Kg 7 - 11
23.1 - 40.8Kg 6 - 10
>40.8Kg 5 - 10
Geriatic <9.5Kg 14 - 20
9.5 - 22.7Kg 12 - 20
23.1 - 40.8Kg 10 - 20
>40.8Kg 10 - 16
Calculated >40.8Kg 17 - 20

Equations: <9.5Kg Y = 4 * X + 16 [1]
9.5 - 22.7Kg Y = 4.5162 * X + 14.985 [2]
23.1 - 40.8Kg Y = 5.3735 * X + 12.581 [3]
>40.8Kg Y = 7.3706 * X + 4.7751 [4]
>40.8Kg Y = 7.3496 * X + 4.9636 [5]
Equation after extrapolating for ages 17 to 20, using [4]

***** SOME OR ALL OF THE ABOVE EQUATIONS MAY WORK FOR X < 5, BUT THEY MAY NOT
AS THE DATA PROVIDED ON THE SOURCE WEBSITE RELATES ONLY TO "SENIOR" DOGS *****

Reference Page: "Aging Signs"
Main Homepage: "The Senior Dogs Project"

Powerpoint Presentation: K9 Ages In Human Years

Click here to use the "K9 to Human" and "Human to K9" Age Calculator

File Created On 11-Sep-2008 at 17:35:52
Source File: C:\Xlsfiles\Romana's History, etc\[A Dog's Age in Human Years.xls]Data Sheet

Please also feel free to view the chart on the next page.
This chart was shown on "Mornings with Kerri-Anne" on the Nine Network, Australia, sometime ago.


This page 2006, Paul Myers