Science-based calculators
for your dog & cat
Four free tools built on veterinary and research-grade formulas — convert pet years to human years, calculate daily calories, and get food portions by brand. No sign-up, instant results.
Ever wondered how old your dog really is in human terms? The classic “multiply by 7” rule is a myth. Our dog age calculator uses the logarithmic formula published by UC San Diego researchers, the most scientifically accurate canine age calculator method available — adjusted for your dog’s breed size.
Feeding too much — or too little — is one of the most common pet health mistakes. Our dog calorie calculator uses the veterinary RER (Resting Energy Requirement) formula to calculate calories for your dog precisely, then adjusts for activity level, life status (neutered, pregnant, senior…) and even your kibble brand.
Cats age very differently from dogs — and from humans. The first two years of a cat’s life equal roughly 25 human years. Our cat age calculator converts cat years to human years using the AAHA (American Animal Hospital Association) feline life-stage guidelines, giving you an accurate picture of where your cat sits in their life journey.
Cats are obligate carnivores with very specific energy needs that vary widely by age, weight, and whether they’re indoor or outdoor. Our cat calorie calculator — sometimes called a feline calorie calculator — uses the RER formula adapted for cats to deliver a precise daily kcal target, and converts that into grams of your specific cat food brand.
Why use science-based pet tools?
Generic rules like “1 dog year = 7 human years” or bag feeding guides are broad estimates. Our calculators use the same formulas veterinarians and researchers rely on.
Dog age uses UC San Diego’s logarithmic model. Calorie needs use the veterinary RER formula. Cat age follows AAHA life-stage guidelines.
Breed size, activity level, life status (neutered, pregnant, senior), and even your exact kibble brand — every variable is factored in.
No account, no subscription, no waiting. Type in your pet’s details and get your answer in seconds — on any device.
🐶 Dog Years → Human Years
| Dog age | Small | Medium | Large |
|---|---|---|---|
| 1 year | 15 | 15 | 15 |
| 3 years | 28 | 28 | 25 |
| 5 years | 36 | 36 | 33 |
| 8 years | 48 | 48 | 45 |
| 10 years | 56 | 56 | 50 |
| 15 years | 76 | 73 | — |
🐱 Cat Years → Human Years
| Cat age | Human years | Life stage |
|---|---|---|
| 1 year | 15 | Kitten |
| 2 years | 24 | Junior |
| 5 years | 36 | Prime |
| 7 years | 44 | Mature |
| 10 years | 56 | Senior |
| 15 years | 76 | Geriatric |
Frequently asked questions
Free Pet Calculators: Dog Age, Cat Age, Dog Calories & Cat Calories
Petsfloo’s free pet tools cover the four most searched pet health questions. Whether you want to convert dog years to human years, find out your cat’s age in human years, calculate calories for your dog, or get a precise daily food portion for your cat — each tool is built on the same formulas used by vets and published researchers.
Dog Age Calculator — Dog Years to Human Years
The dog age calculator converts your dog’s age using UC San Diego’s logarithmic model, the most scientifically accurate canine age calculator method available. Results adjust for small, medium, large, and giant breeds, because a 10-year-old Chihuahua and a 10-year-old Great Dane are at very different biological stages.
Cat Age Calculator — Cat Years to Human Years
Our cat age calculator converts cat years to human years following the AAHA feline life-stage model. Getting your cat’s age in human years helps you understand when to shift to senior food, schedule more frequent vet visits, or adjust activity levels — critical decisions that depend on your cat’s true biological age.
Dog Calorie Calculator — Calculate Calories for Your Dog
The dog calorie calculator goes beyond generic bag guidelines. As a precise canine calorie calculator and dog kcal calculator, it accounts for your dog’s exact weight, activity level, and life status to produce a personalized daily caloric target — then converts that into grams of your specific kibble brand.
Cat Calorie Calculator — Feline Nutrition Made Simple
Our cat calorie calculator — also called a feline calorie calculator or cat nutrition calculator — uses the RER formula adapted for cats. It factors in whether your cat is indoor or outdoor, neutered or intact, kitten or senior, giving you a daily kcal target and corresponding food portion for the most popular brands.