One of the most common questions dog owners ask is: "How much should I feed my dog?" The answer isn't as simple as following the feeding guide on the bag. Every dog is unique, with different energy needs based on age, weight, activity level, metabolism, and health status.
This comprehensive guide will help you calculate the right portions for your dog and adjust them over time to maintain optimal health and weight.
Understanding Caloric Needs
Dogs, like humans, need a specific number of calories each day to maintain their weight and energy levels. Feeding too much leads to obesity; feeding too little can cause malnutrition and energy deficiency.
Resting Energy Requirements (RER)
The foundation for calculating your dog's food needs is the Resting Energy Requirement (RER)—the number of calories your dog needs at rest.
RER Formula: RER = 70 x (body weight in kg)^0.75
For a 20 kg (44 lb) dog: RER = 70 x (20)^0.75 = 70 x 11.9 = 662 calories/day
Daily Energy Requirements (DER)
Once you know the RER, multiply it by a factor based on your dog's life stage and activity level:
| Life Stage / Activity Level | Multiplier |
|---|---|
| Puppy (0-4 months) | 3.0 x RER |
| Puppy (4-12 months) | 2.0 x RER |
| Adult (neutered/spayed) | 1.6 x RER |
| Adult (intact) | 1.8 x RER |
| Senior (neutered/spayed) | 1.4 x RER |
| Active/Working dog | 2.0-5.0 x RER |
| Pregnant dog (first 42 days) | 1.8 x RER |
| Pregnant dog (last 21 days) | 3.0 x RER |
| Lactating dog | 4.0-8.0 x RER |
| Weight loss | 1.0 x RER (for ideal weight) |
Step-by-Step: Calculate Your Dog's Portions
Step 1: Calculate RER
Convert your dog's weight to kilograms (divide pounds by 2.2), then use the RER formula.
Step 2: Determine the Multiplier
Choose the appropriate multiplier from the table above based on your dog's age, activity level, and whether they're spayed/neutered.
Step 3: Calculate Daily Calories (DER)
Multiply RER by your chosen multiplier to get total daily calories needed.
Step 4: Check Your Dog Food's Calorie Content
Look on the dog food bag for "calories per cup" or "kcal/kg." This is usually found in the guaranteed analysis or feeding guidelines section.
Step 5: Calculate Portions
Cups per Day = Daily Calories Needed / Calories per Cup
Practical Examples
Example 1: Adult Labrador (30 kg / 66 lbs, neutered, moderate activity)
- Step 1: RER = 70 x (30)^0.75 = 70 x 15.6 = 1,092 calories
- Step 2: Adult neutered = 1.6 multiplier
- Step 3: DER = 1,092 x 1.6 = 1,747 calories/day
- Step 4: Dog food contains 380 calories/cup
- Step 5: 1,747 / 380 = 4.6 cups per day
- Split into 2 meals: 2.3 cups twice daily
Example 2: Puppy Beagle (8 kg / 17.6 lbs, 6 months old)
- Step 1: RER = 70 x (8)^0.75 = 70 x 5.3 = 371 calories
- Step 2: Puppy 4-12 months = 2.0 multiplier
- Step 3: DER = 371 x 2.0 = 742 calories/day
- Step 4: Puppy food contains 420 calories/cup
- Step 5: 742 / 420 = 1.8 cups per day
- Split into 3 meals: 0.6 cups three times daily
Example 3: Senior Chihuahua (3 kg / 6.6 lbs, spayed, low activity)
- Step 1: RER = 70 x (3)^0.75 = 70 x 2.3 = 161 calories
- Step 2: Senior neutered = 1.4 multiplier
- Step 3: DER = 161 x 1.4 = 225 calories/day
- Step 4: Small breed food contains 450 calories/cup
- Step 5: 225 / 450 = 0.5 cups per day
- Split into 2 meals: 1/4 cup twice daily
Adjusting for Individual Needs
The calculations above are starting points. Every dog is different, and you'll need to monitor and adjust based on:
Body Condition Scoring
- Underweight: Ribs, spine, and hip bones easily visible; no body fat; obvious waist and abdominal tuck
- Ideal weight: Ribs easily felt with slight fat covering; waist visible from above; abdominal tuck visible from side
- Overweight: Ribs difficult to feel under fat; waist barely visible; abdominal tuck may be absent
- Obese: Ribs not palpable under heavy fat; no waist; abdomen distended; fat deposits on limbs and base of tail
When to Increase Food
- Dog is losing weight unintentionally
- Ribs are very prominent
- Energy levels seem low
- Activity level has increased significantly
- Cold weather (outdoor dogs need more calories)
When to Decrease Food
- Dog is gaining weight
- Ribs are difficult to feel
- Loss of visible waist
- Activity level has decreased
- After spaying/neutering (metabolism slows ~25%)
Make Small Adjustments
When adjusting portions, change by no more than 10-15% at a time. Wait 2-3 weeks before assessing results and making further changes. Rapid changes can upset your dog's digestive system.
Feeding Schedules by Age
Puppies (8 weeks to 6 months)
- Frequency: 3-4 meals per day
- Why: Small stomachs, high energy needs, unstable blood sugar
- Tip: Consistent meal times help with house training
Young Adults (6 months to 1 year)
- Frequency: 2-3 meals per day
- Why: Still growing but stomach capacity increasing
- Tip: Transition to adult food around 12 months (18-24 months for large breeds)
Adults (1-7 years)
- Frequency: 2 meals per day
- Why: Reduces hunger, aids digestion, prevents bloat
- Tip: Maintain consistent times (e.g., 7am and 6pm)
Seniors (7+ years)
- Frequency: 2-3 smaller meals per day
- Why: Easier digestion, stable blood sugar
- Tip: Consider senior-specific formulas with joint support
The Bottom Line
Calculating proper portions takes a bit of math, but it's worth the effort. Start with the calculations, then monitor your dog's weight and body condition over time. The feeding guide on dog food bags is a starting point, but your individual dog's needs may vary significantly.
When in doubt, consult your veterinarian—especially if your dog needs to lose or gain weight, has health conditions, or you're unsure about the right approach.