Dog BMI Calculator
Calculate your dog's BMI and compare it to healthy ranges for their breed. Find out if your dog is underweight, ideal, or overweight in seconds.
Use CalculatorChoose dog or cat first, then enter the details that match your pet's species, weight, routine, and current situation.
Achieving healthy weight loss in dogs and cats requires a structured, evidence-based plan - not just 'feeding less.' The Step Weight Loss Calculator generates a personalized calorie-restricted feeding plan targeting safe, gradual weight loss while preserving muscle mass, avoiding nutritional deficiencies, and keeping the animal comfortable throughout the process. It also tracks expected milestones to help you monitor progress and adjust the plan if needed.
Weight Loss Principles for Dogs and Cats
Use the table below to compare Weight Loss Principles for Dogs and Cats.
| Principle | Dogs | Cats | Rationale |
|---|---|---|---|
| Caloric restriction target | RER x 1.0 (using ideal weight, not current) | RER x 0.8 (using ideal weight) | Reduces calories below maintenance while meeting baseline metabolic needs |
| Safe weight loss rate | 1-2% of body weight per week | 0.5-1% of body weight per week | Faster loss risks muscle wasting (dogs) and hepatic lipidosis (cats) |
| Minimum safe daily calories | RER of current weight at bare minimum | RER of current weight at bare minimum | Going below RER is dangerous; inadequate protein causes muscle catabolism |
| Protein level | Maintain high protein DM% | Maintain high protein DM% | Preserves muscle mass during caloric restriction |
| Feeding frequency | 2-3 meals/day | 3-5 small meals/day | Reduces hunger; maintains metabolism; prevents food obsession |
| Re-evaluation interval | Every 2-4 weeks | Every 2-4 weeks | Adjust if losing too fast or not losing; BCS reassessment each visit |
Step-by-Step Weight Loss Plan: Sample 10 lb Overweight Dog
Use the table below to compare Step-by-Step Weight Loss Plan: Sample 10 lb Overweight Dog.
| Step | Action | Example (10 lb overweight dog, ideal weight 40 lbs) |
|---|---|---|
| 1. Determine ideal weight | BCS-guided target; vet assessment | BCS currently 7/9; ideal weight is approximately 40 lbs |
| 2. Calculate ideal weight RER | 70 x (kg)^0.75 | 70 x (18.2)^0.75 = 70 x 7.67 = 537 kcal/day RER |
| 3. Apply weight loss multiplier | RER x 1.0 for dogs | 537 kcal/day target |
| 4. Choose appropriate food | Measure by calories, not cups | If current food is 350 kcal/cup: 537 / 350 = 1.5 cups/day |
| 5. Split into meals | 2-3 meals/day | 0.75 cup morning, 0.75 cup evening |
| 6. Account for treats | 10% maximum calorie allowance from treats | 54 kcal from treats; 1-2 small dental chews |
| 7. Weigh monthly | Track progress against 1-2% per week target | Target loss: 0.4-0.8 lbs per week for this dog |
Why Cats Need Extra Caution During Weight Loss
Hepatic lipidosis (fatty liver disease) is uniquely dangerous in cats. When cats do not eat enough - either voluntarily (food refusal) or due to aggressive caloric restriction - their bodies mobilize fat to the liver faster than it can process, causing life-threatening liver failure. Signs include jaundice (yellow tinge to skin/eyes), vomiting, and profound lethargy. The safe weight loss rate in cats (0.5-1% per week) is specifically set to prevent this. If a cat on a weight loss plan stops eating voluntarily, contact your vet immediately.
Prescription Weight Loss Diets
Use the table below to compare Prescription Weight Loss Diets.
| Product | Species | Key Feature | How It Helps |
|---|---|---|---|
| Hill's Metabolic | Dogs and cats | Alters gene expression to promote fat burning | Clinically trialed; average 28% body fat reduction in 2 months in studies |
| Hill's r/d | Dogs and cats | High fiber, calorie-restricted | Increases satiety; reduces hunger on caloric deficit |
| Royal Canin Satiety | Dogs and cats | Very high fiber, low calorie density | Allows larger food volume at lower calories - helps hunger management |
| Purina OM (Overweight Management) | Dogs and cats | High protein, low fat | Muscle mass preservation during weight loss |
Frequently Asked Questions
My dog begs constantly on the diet. How do I manage this?
Divide the daily allowance into 3 smaller meals instead of 2 to reduce inter-meal hunger. Use slow-feeder bowls to extend mealtime. Replace caloric treats with low-calorie alternatives (plain rice cakes, carrot sticks for dogs). Provide food puzzle toys that extend the eating experience mentally. Most dogs adapt to the new caloric level within 2-4 weeks.
My cat has not lost weight in 6 weeks. What should I do?
Most common reasons: someone in the household is feeding extra portions without communicating, the cat is accessing another pet's food, treat calories are not being counted, or the calculated MER for that individual cat is slightly above average. Recount all food sources meticulously for one week. If genuinely on target calories with no loss, have your vet check thyroid and adrenal function.
Note: Weight loss should be gradual and based on species, body condition, diet, activity, and health history.
Helpful related calculators
Continue with Dog BMI Calculator, Body Condition Score in Dogs, MER Calculator for Dogs for the next practical step.
