Dog Food Calculator
How many calories your dog needs per day, plus a rough cup count — using veterinary RER × MER formulas. Adjustable for life stage and activity, because a 60-lb sled dog and a 60-lb couch potato need wildly different amounts.
How the calculation works
The calculator uses two veterinary nutrition formulas in sequence:
Step 1: RER (Resting Energy Requirement)
This is what your dog burns just existing — sleeping, breathing, basic organ function. The formula is:
RER = 70 × (body weight in kg)0.75
For a 20 kg (44 lb) dog, RER = 70 × 200.75 = 662 kcal/day.
Step 2: MER (Maintenance Energy Requirement)
RER alone isn’t enough — dogs eat more than they burn at rest. MER multiplies RER by a factor based on life stage and activity:
| Life stage / activity | MER × RER |
|---|---|
| Puppy under 4 months | 3.0 |
| Puppy 4-12 months | 2.0 |
| Adult — inactive / weight loss | 1.2 |
| Adult — normal pet | 1.6 |
| Adult — active (1+ hr/day) | 2.0 |
| Adult — working dog | 2.5–8.0 (we use 4.0) |
| Senior | 1.4 |
| Pregnant (last trimester) | 1.8 |
| Lactating mother | 4.0+ |
Step 3: Convert calories to cups
The calorie content of dog food varies enormously — premium dry kibble can be 380-420 kcal/cup, weight-management kibble around 300-340, raw and grain-free formulas 400-500. Check the kcal/cup printed on your bag and enter it above for accurate cup counts.
The most common feeding mistakes
- Following the bag chart blindly. Bag charts target the upper end of average needs and don’t adjust for spay/neuter, activity, or environment. They cause widespread overfeeding.
- Free-feeding. Leaving food out all day prevents weight management and removes the appetite cue that signals illness.
- Forgetting treats and table scraps. Treats should be no more than 10% of daily calories. Most "occasional" treats end up much higher.
- Not adjusting after spay/neuter. Calorie needs typically drop by 25-30% after spay/neuter — keep the same portions and your dog will gain weight steadily.
- Switching life stages too late. Senior dogs lose muscle and burn fewer calories; transition to senior food and reduced portions around 7-10 years (sooner for giant breeds).
Body condition matters more than the scale
The calculator gives you a starting point. Adjust up or down based on the Body Condition Score — you should be able to feel ribs easily without pressing hard, see a clear waist when looking down, and see a tucked-up belly from the side. Reweigh and re-score every 4-6 weeks.
Frequently asked questions
How much should I feed my dog?
A healthy adult dog needs roughly 25-30 calories per pound of body weight per day. Working dogs and puppies need significantly more; senior or overweight dogs need less. The most accurate way is the RER × MER formula this calculator uses — it accounts for size, life stage, and activity individually.
What is RER and MER?
RER (Resting Energy Requirement) is the calories your dog burns just existing — calculated as 70 × (weight in kg)^0.75. MER (Maintenance Energy Requirement) multiplies RER by a factor based on life stage and activity. Most adult pet dogs sit at MER = 1.6 × RER. Active working dogs can hit 4-8 × RER.
Should I feed once or twice a day?
Twice a day is the standard recommendation for most adult dogs — once in the morning, once in the evening. Puppies under six months need three meals daily. Some giant breeds with bloat risk benefit from smaller meals more frequently. Avoid free-feeding; it makes weight management nearly impossible.
Why does my dog food bag say to feed more?
Feeding charts on dog food bags are typically generous — they target the upper end of average needs and don't adjust for spay/neuter or activity. About 50% of US dogs are overweight, partly because of this. Trust the calculator (or your vet's recommendation) over the bag chart, and adjust based on body condition.
What if I feed wet food or raw?
The total calorie target stays the same. Check the calorie content per cup or per ounce on the label — wet food typically has 350-450 kcal per can; raw food varies widely. Divide your dog's daily calorie target by the food's kcal/cup to get cups, or by kcal/ounce for ounces.