Estimate the Mature Height of a Yearling

Estimate mature height of yearling

In this post you’ll learn how to estimate the mature height of a yearling. Mature height refers to how tall the yearling will be when she’s all grown up.

Math Talk – estimate: to make a close guess or rough calculation often based on rounding.
Horse Talk – yearling: a young horse of either sex that is between one and two years old.

One of the reasons this method works is that a yearling’s leg measurement is about the same as it will be as an adult. After the first year, most of a horse’s growth takes place through the body as it becomes fuller and deeper and the withers become more pronounced.


Ergots are small growths on the back of the fetlock, and are often covered by hair like on this horse. When you feel them, they feel a lot like an eraser on the end of a wooden pencil.

Step 1: Using a string or measuring tape, measure the yearling from the ergot to the elbow. Hold onto the string with your fingers to mark this length. If you’re using a tape measure, take note of the measurement.(line A above)

Step 2: Place one end of the string or tape measure at the elbow and raise the string straight up to where your fingers are marking the length you measured in step one. This is indicated as line B in the picture above. Add 1 inch and you have the yearling’s approximate mature height at the withers when she’s all grown up.

1. You’ve taken the measurements. Now it’s time to calculate the estimate. Write the math calculation described in these steps as a math sentence.

In a previous post Horse Lover’s Math gave a simple math equation for how to estimate the mature height of a foal. Estimating the mature height of a yearling is probably a little more accurate than estimating the mature height of a foal, especially in horses that mature to approximately 15 to 16.3 hands.

2. How many inches are in a hand?

Imagine you’ve measured a yearling from the ergot to the elbow (line A) and got a measurement of 27 inches.

3. Estimate the mature height of the yearling. Give your answer in hands.

If you had the chance, it would be interesting to estimate the height of a foal, and then a year later, use the method described in this post to estimate the height of the same horse as a yearling. I wonder how close the results would be!

Common Core:
4.OA.A.3 Solve multistep word problems posed with whole numbers and having whole-number answers using the four operations, including problems in which remainders must be interpreted.
5.MD.A.1 Convert among different-sized standard measurement units within a given measurement system, and use these conversions in solving multi-step, real world problems.
6.EE.B.6 – Use variables to represent numbers and write expressions when solving a real-world or mathematical problem; understand that a variable can represent an unknown number.

SilverMorgan; CC BY 2.0
Pasterns; CC BY-SA 3.0

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2 Responses to “Estimate the Mature Height of a Yearling”

  1. Tonnie Casey
    May 17, 2016 at 7:39 pm #

    Your “elbow” in your picture is the back of the knee. The elbow is much higher next to the body.

  2. HLM
    May 18, 2016 at 4:27 pm #

    Thanks for your comment. The ‘A’ labelling the line from the ergot to the elbow was positioned beside the knee, causing confusion. As a result I’ve created a new image. The lines are more clearly labelled, and the position of the ergot and elbow pointed to. I’ve also added centimetres to the measurement as well. This new image is an improvement—so thanks for pointing this out!

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