Bodyweight for Horses

Estimating bodyweight is something even the most experienced equine professionals find difficult to do, and yet an accurate estimate of bodyweight is a crucial for feeding, worming and administering medications correctly.

The most accurate way to measure your horse's bodyweight is to use a set of livestock scales; however few of us have the luxury of a set of scales at our disposal. Fortunately, two methods of estimating mature horse bodyweight using measurements of the horse's girth and length have been developed and are summarised below.

Method 1: Girth Measurement

The first method involves a simple girth measurement. The girth measurement should be made by placing a measuring tape (or a piece of string that you can measure later) around the horses girth, just behind the withers and elbows as shown in Figure 1 and taking the measurement after the horse breathes out. Once you have taken the measurement, round it up or down to nearest 10 cm and use the table below to estimate your horse's bodyweight.

Bodyweight (kg)

Girth Length
(cm)

Mature Horses

Pregnant Mare
(8 months)

Pregnant Mare
(9 months)

Pregnant Mare
(10 months)

Pregnant Mare
(11 months)

80

45

46

48

50

53

90

70

71

74

78

82

100

90

92

95

100

105

110

120

122

127

133

140

120

150

153

159

167

176

130

185

189

196

205

216

140

230

235

244

255

269

150

285

291

302

316

333

160

345

352

366

383

404

170

410

418

435

455

480

180

475

485

504

527

556

190

545

556

578

605

638

200

615

627

652

683

720

 


Figure 1: Shows where to take the girth and length measurements to estimate the bodyweight of your horse.

Method 2: Girth and Length Measurement

A slightly more accurate method of estimating bodyweight is to take a girth and length measurement. Again, the girth measurement is taken after the horse breathes out and the length measurement should extend from the point of the horses shoulder to the point of the buttocks as shown in Figure 1. Both measurements should be made in centimetres. Once you have obtained the measurements, you can use the following equation to estimate bodyweight:

Bodyweight (kg) = [Girth (cm) x Girth (cm) x Length (cm)] ¸ 11 800