MER Calculator for Dogs

This interactive tool has been designed to help you with nutritional recommendations. Enter your patient's age group, weight, body condition score (BCS), and dietary goals (maintain or lose weight) to reveal estimated ideal weight if pet were in ideal BCS, and estimated daily caloric needs (maintenance energy requirements, or MER).

Required fields

Estimated Age of Reaching Senior Status:

Breed Size: Age (years)

  • Toy/small breeds: 8+ years
  • Medium breeds: 7+ years
  • Large/giant breeds: 6+ years
Purina Body Condition System for Dogs

If a goal of “maintain weight” is selected for a pet with a BCS of 6 or 7, slow weight loss could occur since MER will be based on a lower body weight. However, selecting “lose weight” as the goal will provide greater calorie restriction, which may facilitate faster weight loss. Calories should be gradually decreased for safe, effective weight loss. If a pet is underweight, selecting “maintain/gain weight” should encourage slow weight gain since MER will be based on a higher body weight. However, desired weight gain may not occur until contributing conditions are identified and managed, especially in pets with a BCS of 1 or 2. For dogs, ideal body condition score may depend on breed.

MER Calculator for Cats

This interactive tool has been designed to help you with nutritional recommendations. Enter your patient's age group, weight, body condition score (BCS), and dietary goals (maintain or lose weight) to reveal estimated ideal weight if pet were in ideal BCS, and estimated daily caloric needs (maintenance energy requirements, or MER).

Required fields

Purina Body Condition System for Cats

If a goal of “maintain weight” is selected for a pet with a BCS of 6 or 7, slow weight loss could occur since MER will be based on a lower body weight. However, selecting “lose weight” as the goal will provide greater calorie restriction, which may facilitate faster weight loss. Calories should be gradually decreased for safe, effective weight loss. If a pet is underweight, selecting “maintain/gain weight” should encourage slow weight gain since MER will be based on a higher body weight. However, desired weight gain may not occur until contributing conditions are identified and managed, especially in pets with a BCS of 1 or 2.