Pet Food Cost Calculator (Dog / Cat)
Estimate how much your dog or cat should eat, how long a bag of dry food or a case of cans lasts, and what feeding really costs per day, month, year and over the years ahead, from your pet’s weight, life stage and the food’s calories. Handles dry, wet and mixed feeding, treats, several pets and auto-ship discounts.
How it works
RER = 70 × (kg)^0.75 · Daily kcal = RER × life-stage factor (adult neutered: dog 1.6, cat 1.2) · Food kcal = daily kcal × (1 − treat share) · Cups/day = dry kcal ÷ kcal per cup · Cans/day = wet kcal ÷ kcal per can · Days per bag = (bag lb × 4 cups) ÷ (cups/day × pets) · Monthly cost = daily cost × 30.44, after any discount, plus treats
A pet’s energy need starts from its resting energy requirement (RER), which scales with body weight to the three-quarter power: 70 × weight in kg^0.75. It is then multiplied by a factor for life stage and activity, the method in the Merck Veterinary Manual and WSAVA guidelines: about 1.6 for a typical neutered adult dog and 1.2 for a neutered adult cat, more for intact, active and working animals and for puppies and kittens, and less for inactive or senior pets and for weight loss (where you use the target weight). Dividing the daily calories by the calories per cup (dry) or per can (wet) printed on the label gives the real portion, which is often smaller than the feeding chart on the bag. From the portion, the calculator works out how many days a bag lasts, cans per month, and the cost per day, month and year, for one pet or several. You can mix dry and wet food by share of calories, set aside part of the calories for treats, add the money spent on treats and chews, apply an auto-ship discount, and add up the cost over several years with a yearly price increase. The cost per 1,000 kcal makes foods of different sizes and prices directly comparable.
Worked example
A 50 lb dog is 22.7 kg, so RER = 70 × 22.7^0.75 ≈ 728 kcal, and at the neutered-adult factor of 1.6 about 1,165 kcal a day. At 365 kcal per cup that is 3.19 cups daily. A 30 lb bag holds roughly 120 cups, lasting about 38 days; a $50 bag therefore costs about $40 a month, $485 a year and $4,850 over ten years. Feeding a quarter of the calories as 400 kcal cans at $2.50 instead adds about 0.73 cans a day and raises the monthly cost to about $86, because wet food here costs $6.25 per 1,000 kcal against $1.14 for the kibble.
Sources: Merck Veterinary Manual — Nutritional requirements of small animals · WSAVA Global Nutrition Guidelines · Omni Calculator — Cat calorie calculator
Frequently asked questions
How long will a bag of dog food last?
Divide the number of cups in the bag (about four cups per pound of dry kibble) by your dog’s daily cups. A 30 lb bag holds roughly 120 cups, so a dog eating three cups a day gets about 40 days from it. Two dogs of that size empty it in about 20 days.
How many calories does my pet need?
For a typical neutered adult, multiply 70 × (body-weight-in-kg)^0.75 by about 1.6 for dogs or 1.2 for cats. Puppies, kittens, working dogs and unspayed animals need more; seniors, inactive and overweight pets need less. Pick the life stage in the calculator to see the figure, and confirm with your vet.
Is wet food more expensive than dry?
Usually, per calorie. Kibble often costs around $1–2 per 1,000 kcal while cans and pouches commonly cost $4–10, because wet food is about 75–80% water. The calculator shows the cost per 1,000 kcal for each so you can compare your own foods.
How much of my pet’s diet can be treats?
A common veterinary rule is no more than 10% of daily calories. Enter the share under More options: the calculator lowers the main food portion so the total calories stay the same.
Why is my pet’s portion smaller than the bag suggests?
Feeding charts assume active, ideal-weight animals and err high. Calculating from calories usually gives a smaller, more accurate portion — one reason many pets are overfed. Adjust to keep your pet at a healthy body condition.
Related calculators
Educational estimate only. Portion needs vary with age, breed, activity and health — consult your veterinarian.