Purina MER Calculator for Cats
The Purina MER Calculator for Cats estimates Daily Caloric Needs based on current weight, age, and reproductive status. This tool helps cat owners provide precise nutrition for optimal health and vitality. Whether you are managing weight loss, supporting a kitten’s growth, or maintaining an active adult, this calculator offers accurate daily feeding guidelines tailored to your cat's specific life stage.
How Daily Caloric Needs Is Calculated
Daily Caloric Needs (MER) represents the total metabolizable energy your cat requires each day to maintain body function and support activity levels. To find this number, we use a standard scientific method that establishes a baseline energy requirement first.
MER = RER × Multiplier
Where:
- RER = Resting Energy Requirement (70 × weight in kg^0.75)
- Multiplier = Specific factor based on activity and life stage
First, we calculate the RER based solely on body weight, which covers basic organ function. Then, we multiply this baseline by a factor ranging from 0.8 to 3.0, accounting for specific needs like pregnancy, illness, or daily activity. This step ensures we do not overfeed a sedentary cat or underfeed a growing kitten.
Finally, the result is converted into standard food measurements. This method is widely used by veterinarians to ensure nutritional plans are accurate and safe.
What Your Daily Caloric Needs Means
Your result is the precise number of kilocalories your cat needs to consume daily to reach or maintain their goal weight. You can use this total to measure out exact portions of dry or wet food, removing the guesswork from mealtime.
Weight Loss
If your cat is overweight, the calculator uses a multiplier to create a calorie deficit. Aim for the calculated amount to help your cat lose weight safely, targeting about 1% to 2% of body weight loss per week.
Maintenance
For a healthy, neutered adult cat, the result typically uses a multiplier of 1.2. Stick to this number to keep your cat at a stable weight, ensuring they get enough energy without excess calories that lead to weight gain.
Growth & Lactation
Kittens and nursing mothers require significantly more energy. Your result will often be much higher, reflecting multipliers of 2.0 to 3.0, to support rapid tissue development or milk production.
Important: Always monitor your cat’s body condition and adjust intake if you notice unintended weight changes. These numbers are estimates, and individual metabolism can vary.
This calculator provides nutritional estimates based on standard veterinary guidelines. It is not a substitute for professional veterinary advice. Please consult your veterinarian to determine the specific dietary needs of your pet, especially if they have underlying health conditions.
Check your cat's weight every 2 to 4 weeks to ensure the feeding plan is working effectively.