My Weight Tape

One of the common ways to measure a horse is to use a weight tape. You place a tape around the horse's heart 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 7/161 1/280
30 1/21 1/1690
31 5/81 1/8100
32 5/81110
33 5/81120
34 14/161 1/4135
36 1/81 1/4150
37 1/41 1/8165
38 1/21 1/4180
39 3/41 1/4200
41 3/161 7/16220
42 09/161 7/16245
43 15/161 3/8270
45 1/41 3/8295
46 1/21 1/4320
481 1/2350
49 3/81 3/8380
50 11/161 5/16410
52 3/81 11/16440
54 1/161 11/16475
54 15/160 14/16510
56 3/41 13/16550
57 3/41590
591 1/4630
60 1/21 1/2670
61 15/161 1/2715
63 3/81 7/16760
64 3/41 7/16810
66 5/161 09/16860
67 14/161 09/16910
69 5/161 7/16960
70 3/41 7/161015
72 1/41 1/21070
73 11/161 1/21130
75 1/41 09/161190
76 3/41 09/161250
78 1/41 1/21310
79 3/41 1/21375
81 1/41 1/21445
82 3/41 1/21515
84 1/41 1/21590
85 3/41 1/21665
87 1/41 1/21745
88 3/41 1/21830
90 1/41 1/21920
91 3/41 1/22010
93 1/41 1/22105
94 3/41 1/22200
96 1/41 1/22300

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!.



The classic formula

The classic formula for estimating a horse's weight was provided but "david" on the Draft Resource Chat Board, and is the same as the classic 1977 The Draft Horse Primer

second method

Posted by david on January 02, 2001 at 17:29:12:

In Reply to: What is the formula for determining a horse's weight? posted by cynthia v on January 01, 2001 at 19:13:43:

: I had it saved but lost it. I would like to try it on our Percheron cross 2 year old. We are going to take her and have her weighed on a truck scale where we buy our fertilizer and I am curious about the accuracy. Will it work on any breed of horse? I'm sorry for being reduntant. Thank you in advance.

there is another method where you start by measuring the heart girth as described earlier - measure in inches. then measure the length of the horse from the center of the chest down along the side of the horse to the furthermost point of the hip (back of the thigh). using these two measurements - there is a formula that is pretty accurate to guess the weight. multiply the heart girth times itself. then multiply that number by the length. divide this number by 330 and that gives you the weight. i have found this to be more accurate that the weight tape as a general rule. (i may be off on the exact points to measure the length of the horse - but you get the idea)




Estimating full adult height

Debra asked on the Draft Resource Chat Board how to estimate final height of a horse from the length of the canon bone.

Re: Whats the formula for calculating the final height of a horse?

Posted by Alice S on March 01, 2001 at 10:06:31:

In Reply to: Whats the formula for calculating the final height of a horse? posted by debra on February 28, 2001 at 14:25:19:

Measure from the middle (indent) of the knee to the bottom of the coronet band. Whatever that is in inches is what the height will be in hands, i.e., 16 inches = 16 hands. In other words this measurement is 25% of the horse's adult height.

Alice S.

Follow Ups:

Re: Whats the formula for calculating the final height of a horse? George's Gal 07:32:22 3/02/2001 (2)
What I've heard... Tammi 08:51:56 3/02/2001 (1)
Incorrect....go from center of knee with straight drop to top of coronet band...do NOT follow contour of leg NOM Ruler 02:48:00 3/04/2001 (0)



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Comments: Brad
Updated: 2001-08-16 - bk
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