The Chew Meter, or Chew Strength, was determined based on field testing. We tested a variety of extreme chewers to determine how well the toys stood up under vigorous chewing. If our most spirited and strongest chewers damaged the toy, we gave the toy a medium strength assessment. If the toy stood up under hearty chewing, it was given a hard strength assessment.
Due to the vast diversity of size, weight, strength, age and activity level of dogs, there is no formula that can be used to calculate precise strength levels. The Chew Meter is not breed specific; it's based on power and force of the individual dog's chewing style.