As a breeder, one of the questions I hear almost every day is:

“How tall and how heavy will my puppy be when fully grown?”

Predicting weight is particularly difficult. We have no way of knowing whether the new owner will feed the puppy until it resembles a well-rounded little piglet, or whether it will grow into a fussy creature who turns its nose up at every meal and rattles its bones dramatically

Predicting adult height, however, has occupied the minds of both pet owners and show breeders for many years. Through countless observations, breeders have noticed several interesting patterns.

Naturally, none of these methods comes with a 100% guarantee. Puppies do not read growth charts and occasionally decide to surprise everyone. However, they can give us a reasonable idea of a puppy’s eventual size.

In my experience with Toy Poodles, these predictions are accurate to within approximately one centimetre in about 85% of cases.

So, let me share a few of these mysterious breeder “magic rituals” with you. Feel free to try them if you ever have the opportunity!

The six-week prediction

The first attempt can be made when the puppy is exactly six weeks old.

It is best to have two people doing the measuring, as six-week-old puppies are not famous for standing still. Measure the puppy’s height at the withers as accurately as possible, then simply double it.

For example:

14 cm at six weeks × 2 = an estimated adult height of 28 cm.

The eight-week prediction

The next measurement should be taken on the exact day the puppy turns eight weeks old.

Measure the height at the withers and then:

add 10 cm for a girl

add 12 cm for a boy

For example, a female puppy measuring 15 cm at eight weeks may grow to approximately 25 cm.

If the six-week and eight-week calculations produce the same result, the likelihood of the prediction being correct becomes higher.

The height-and-weight comparison

There is another theory that compares a puppy’s height and weight at eight weeks.

Take the puppy’s weight in kilograms and remove the decimal point, then compare that number with the height in centimetres.

For example, a puppy measuring 13 cm and weighing 1.2 kg gives us the numbers 13 and 12.

If the numbers are close, the puppy has a good chance of remaining within the Toy Poodle height range of up to 28 cm. If the difference is greater than two, the puppy may be more likely to grow above the Toy limit.

I must admit, this particular method has not worked especially well for me—but perhaps other breeders have had better luck with it!

The three-month prediction

At three months, divide the puppy’s current height by three, then add the result back to the original height.

For example:

18 cm ÷ 3 = 6 cm

18 cm + 6 cm = 24 cm

The estimated adult height would therefore be approximately 24 cm, give or take one centimetre.

Using this formula, a puppy would need to measure no more than approximately 20 cm at three months to have a good chance of remaining under 28 cm as an adult.

In my experience, this formula is slightly less accurate than the six- and eight-week measurements.

One final observation

A puppy measuring no more than approximately 16 cm at two months, or no more than 20–21 cm at four months, has a good chance of remaining within Toy Poodle height.

Once again, these are breeder rules of thumb—not scientific guarantees. Genetics, growth spurts, nutrition and simple measuring errors can all affect the final result.

Still, these little “magic rituals” can help us make an educated guess about the adult height of a particular puppy while we wait for nature to reveal the final answer