Free dog & cat calculators: food, weight, age & safety
Free pet calculators that run in your browser. Example: a 45 lb neutered adult often needs about 1,075 kcal/day (~3 cups at 350 kcal/cup). Predict puppy weight, estimate feeding calories, convert pet years, and check chocolate risk — with cited sources. Built by Hammad Iqbal.
All calculators
Puppy Weight
Predict adult weight from age in weeks, current weight and breed or size. Growth chart in lb and kg; free, private.
Dog Food
Daily calories and cups from weight, life stage and label kcal per cup. RER/MER factors; lb or kg; free.
Puppy Food
Calculate puppy feeding amounts by current weight and expected adult size using RER and growth multipliers.
Homemade / Raw
Estimate daily homemade or raw ration portions from body weight. Educational only — balance recipes with a vet nutritionist.
Dog Age
Dog years to human years by size with AAHA-style life stages and an optional log curve — not the 7:1 myth.
Cat Age
Estimate your cat’s age in human years with life-stage stages used by veterinary associations.
Cat Food
Estimate daily kcal and feeding amounts for cats by weight, life stage, and body condition goals.
Dog BMI / BCS
Screen body condition with a BMI-style index and the 1–9 BCS scale. Educational helper, not a diagnosis.
Dog Pregnancy
Estimate whelping due date from breeding or ovulation date. Typical gestation is about 63 days.
Chocolate Toxicity
Estimate theobromine dose from chocolate type, amount and weight. Call a vet or poison hotline if your dog ate chocolate.
Water Intake
Estimate typical daily water needs from body weight and activity. Sudden changes warrant a vet visit.
Which pet calculator do I need?
The right calculator depends on the question. To feed a dog, use the dog food calculator. To predict a puppy's adult size, use the puppy weight calculator. For cats, use the cat food calculator. Each shows its formula and sources, and none needs an account. Always confirm feeding and health decisions with your veterinarian.
What you can calculate
PetCalc Tools is a free toolkit for everyday dog and cat questions: how big a puppy may get, how many calories to feed, how old a pet is in human years, and whether chocolate exposure looks concerning. Every tool keeps data on your device, supports lb and kg, and links to the formulas and sources behind the numbers. See our editorial policy and methodology.
Browse by pet
Guides
When Do Puppies Stop Growing?
When puppies stop growing by size class, what affects adult weight, and when to switch from puppy to adult food — with a growth timeline.
How Much to Feed a Puppy
How much and how often to feed a puppy by age and adult size: daily calories, meals per day and signs of overfeeding, plus a free puppy food calculator.
The Dog Years Myth: Why 7:1 Is Wrong
Why the 7:1 dog-years myth fails, what AAHA life stages mean, and how the Wang et al. 2020 log curve (104 Labradors) compares.
Raw Feeding for Dogs: BARF vs Prey
What BARF and prey-model raw feeding mean, pathogen and balance risks, and how portion maths relates to a homemade food calculator (safety first).
Cat Feeding Guide: Calories, Wet vs Dry, and Weight
Cat feeding by life stage: wet vs dry, meal schedules, weight cues, and when to use a cat food calculator for kcal estimates.
Chocolate and Dogs: Why It Is Dangerous
Why chocolate is dangerous for dogs, theobromine by type, symptoms, and when to call ASPCA or Pet Poison Helpline — with a link to the toxicity calculator.
Cat Life Stages: Kitten to Geriatric
AAFP/AAHA-style cat life stages with a cat-years-to-human-years chart, care focus by age, and when to adjust diet or vet visits.
How Much Water Should a Dog Drink?
How much water a dog should drink per day by weight (~50–60 ml/kg), dehydration signs, and when to call your veterinarian.
How Long Are Dogs Pregnant?
Dog pregnancy length (~63 days from ovulation), week-by-week stages, and why ultrasound confirmation with your vet matters.
Dog Body Condition Score Chart
Dog body condition score chart (BCS 1–9) in plain words: ribs, waist, and abdomen cues to screen if your dog is overweight.
Homemade Dog Food Calories Guide
How to estimate homemade dog food calories with RER/MER context, portion maths, and why a veterinary nutritionist must balance recipes.
Kitten Feeding Schedule by Age
Kitten feeding schedule by age: meals per day, weaning notes, calorie multipliers, and when orphan or underweight kittens need a vet.