Dog Nutrition Calculator: Daily Calories & Portions
Calculate your dog's daily calorie needs and recommended food portions based on weight, age, and activity level.
Reviewed by Daniel Agrici, Founder & Lead Developer
Formula
RER = 70 x (Weight in kg)^0.75 | MER = RER x Activity Factor x Life Stage Factor x Condition Factor
Resting Energy Requirement (RER) represents basal metabolic needs calculated using metabolic body weight. Maintenance Energy Requirement (MER) adjusts RER by activity level (1.2-2.5x), life stage (0.8x for seniors, 2-3x for puppies), and body condition (0.7x for obese to 1.2x for underweight). Macronutrients are calculated as percentages of total calories following AAFCO guidelines.
Worked Examples
Example 1: Active Adult Labrador
Problem:Calculate daily nutrition for a 30-kg (66-lb) moderately active adult Labrador at ideal weight.
Solution:RER = 70 x 30^0.75 = 70 x 12.82 = 897 kcal\nMER = 897 x 1.6 (moderate activity) x 1.0 (adult) x 1.0 (ideal weight) = 1,435 kcal/day\nProtein (25%): 359 kcal = 90g\nFat (14%): 201 kcal = 22g\nCarbs (61%): 875 kcal = 219g\nDry food: ~3.8 cups/day\nWater: 30 x 55 = 1,650 ml (~7 cups)
Result:1,435 kcal/day | 90g protein, 22g fat | ~3.8 cups dry food | 1,650 ml water
Example 2: Overweight Senior Dog
Problem:Calculate reduced-calorie nutrition for a 15-kg (33-lb) overweight senior Beagle.
Solution:RER = 70 x 15^0.75 = 70 x 7.62 = 534 kcal\nMER = 534 x 1.4 (light activity) x 0.8 (senior) x 0.8 (overweight) = 478 kcal/day\nProtein (25%): 120 kcal = 30g\nFat (14%): 67 kcal = 7g\nDry food: ~1.3 cups/day\nWater: 15 x 55 = 825 ml (~3.5 cups)
Result:478 kcal/day | 30g protein, 7g fat | ~1.3 cups dry food | 825 ml water
Frequently Asked Questions
How many calories does my dog need per day?
A dog daily caloric needs are calculated using the Resting Energy Requirement (RER) formula: 70 x (body weight in kg)^0.75. This base metabolic rate is then multiplied by factors for activity level and life stage. A sedentary 20-lb dog needs about 340 calories/day, while an active working dog of the same weight might need 850 calories/day. Puppies require 2-3 times the adult calories per kg for growth. Senior dogs typically need 20% fewer calories as their metabolism slows. These are starting points; adjust based on whether your dog is gaining or losing weight.
What is the ideal protein-to-fat ratio for dog food?
For adult dogs, AAFCO recommends minimum 18% protein and 5% fat on a dry matter basis, but most nutritionists recommend higher amounts: 25-30% protein and 12-18% fat for optimal health. Active and working dogs benefit from higher fat content (20-30%) for sustained energy. Puppies need at least 22% protein and 8% fat to support growth. Senior dogs may benefit from higher protein (28%+) to maintain muscle mass, but with moderate fat to prevent weight gain. The remaining calories come from carbohydrates, which while not essential for dogs, provide fiber, vitamins, and readily available energy.
How much water should my dog drink daily?
The general guideline is that dogs should drink approximately 50-60 ml of water per kilogram of body weight per day, or roughly 1 ounce per pound. A 50-lb dog needs about 50 ounces (6+ cups) daily. Water needs increase significantly with exercise, hot weather, dry food diets (which contain only 10% moisture vs. 78% in wet food), pregnancy, lactation, and illness. Signs of dehydration include dry gums, loss of skin elasticity, lethargy, and sunken eyes. Always ensure fresh, clean water is available. Some dogs prefer running water from fountains, which can encourage greater fluid intake.
How often should I feed my dog?
Feeding frequency depends on age and life stage. Puppies under 4 months need 4 meals per day as their small stomachs cannot hold enough food in fewer meals. From 4-12 months, 3 meals per day is appropriate. Most adult dogs do well on 2 meals per day, spaced approximately 12 hours apart. Senior dogs may benefit from 2-3 smaller meals to aid digestion. Lactating mothers may need free-choice feeding or 3-4 meals to meet their extraordinary energy demands. Avoid feeding one large meal per day, especially for large breeds, as this can increase the risk of bloat (gastric dilatation-volvulus), a life-threatening emergency.
References
Reviewed by Daniel Agrici, Founder & Lead Developer · Editorial policy