About & methodology

PetHealthCalculator turns published veterinary guidance into simple, free tools for pet owners worldwide. Every calculator shows its formula, assumptions and sources right next to the result.

Our principles

• Source-based. We cite published veterinary guidance and research where available. Some tools use approximations or our own simplified rules, identified in their assumptions; a citation does not validate every implementation.
• Transparent. Each page lists the exact formula, its assumptions and links to the original source.
• Honest about limits. Where no validated science exists (e.g. rabbit age, fish stocking) we say so.
• Private. No account, no tracking of your pet data — saved profiles stay in your own browser.

Veterinary review status

These tools and breed profiles have not been independently reviewed by a veterinarian. We do not currently have a named veterinary reviewer, credentials or a veterinary review date to publish. Source links are references, not organisational endorsements. Emergency thresholds, dosage calculations and species-specific advice must be confirmed with your vet.

Read our Privacy policy and Terms of use.

Organisations we rely on

World Small Animal Veterinary Association (WSAVA) ↗
Global nutrition guidelines, body condition scoring
American Veterinary Medical Association (AVMA) ↗
Dog age by size
American Animal Hospital Association (AAHA) ↗
Nutrition & weight management, feline life stages
American Association of Feline Practitioners (AAFP) ↗
Feline life stage guidelines
Merck / MSD Veterinary Manual ↗
Toxic doses, gestation, exotic husbandry
House Rabbit Society ↗
Rabbit diet
Association of Avian Veterinarians (AAV) ↗
Bird housing

All cited sources

Medical disclaimer

The information on this site is for general education only. It is not veterinary advice, diagnosis or treatment, and it does not replace an examination by a qualified veterinarian. Individual animals vary. If your pet is unwell or may have eaten something toxic, contact your veterinarian or an animal poison hotline immediately.

Built with love for pets

We’re pet lovers and pet parents who know how much our animals mean to us. We created PetHealthCalculator.com to make helpful pet health tools and information easier for families to access.

The calculators and resources are free to use. If you’ve found them useful and would like to help us keep improving the site, you can support the project with a voluntary contribution.

Your support helps with website hosting, maintaining our tools, researching reliable sources, and developing more resources for pet owners.

Support PetHealthCalculator

Supporting us is completely optional. All tools remain free to use.