My Weight Tape – Horse Measuring

One of the common ways to measure a horse is to use a weight tape. You place a tape around the horse’s girth, from just behind the front legs to the back just back of the withers, and on around to where you started. Using the Purina or other weight tape, you will find that the amount of tape required to go around the horse is a pretty accurate measure of the weight of the horse.

Purina research created the weight tape, using a series of overlapping ‘blocks’ that are marked in a sequence of various weights. A measurement of a horse will fall on two staggered blocks, each with a different weight. The weight of the horse is then the average of the weights in the two blocks.

My Purina tape ran from 80 pounds to 1320. Well, I noticed that each block was a bit more difference in weight from the previous weight, and started extrapolating for the next couple of blocks. I found a regular, predictable pattern. The result is the table you see below.

I use a flat nylon longeline to wrap around the heart girth and mark the circumference on the line (I hold my thumbnail at the place the lines meet). Then I measure from the end of the line to the mark (thumbnail) using a tape measure. Then I spot that heart girth measurement on the table below. The reason for the two-step measure is that Kat doesn’t like the rattling noises from the tape measure, and I don’t like fooling with her and the metal rule.

In 1997 I used the tape & chart to estimate my then 3 yo Belgian mare at 1710 pounds, then weighed her on a scale, and came within 10 pounds.

Inches of Heart Girth Size of Weight Block Weight of the Block
29 7/16 1 1/2 80
30 1/2 1 1/16 90
31 5/8 1 1/8 100
32 5/8 1 110
33 5/8 1 120
34 14/16 1 1/4 135
36 1/8 1 1/4 150
37 1/4 1 1/8 165
38 1/2 1 1/4 180
39 3/4 1 1/4 200
41 3/16 1 7/16 220
42 09/16 1 7/16 245
43 15/16 1 3/8 270
45 1/4 1 3/8 295
46 1/2 1 1/4 320
48 1 1/2 350
49 3/8 1 3/8 380
50 11/16 1 5/16 410
52 3/8 1 11/16 440
54 1/16 1 11/16 475
54 15/16 0 14/16 510
56 3/4 1 13/16 550
57 3/4 1 590
59 1 1/4 630
60 1/2 1 1/2 670
61 15/16 1 1/2 715
63 3/8 1 7/16 760
64 3/4 1 7/16 810
66 5/16 1 09/16 860
67 14/16 1 09/16 910
69 5/16 1 7/16 960
70 3/4 1 7/16 1015
72 1/4 1 1/2 1070
73 11/16 1 1/2 1130
75 1/4 1 09/16 1190
76 3/4 1 09/16 1250
78 1/4 1 1/2 1310
79 3/4 1 1/2 1375
81 1/4 1 1/2 1445
82 3/4 1 1/2 1515
84 1/4 1 1/2 1590
85 3/4 1 1/2 1665
87 1/4 1 1/2 1745
88 3/4 1 1/2 1830
90 1/4 1 1/2 1920
91 3/4 1 1/2 2010
93 1/4 1 1/2 2105
94 3/4 1 1/2 2200
96 1/4 1 1/2 2300

For example, I just measured Kat as 87 3/4″ girth. The two blocks are 1745 and 1830 pounds, the average (Kat’s weight) is 1787 pounds, +/- 50 pounds.

I use this table — have fun with it!.