Disclaimer

Last updated 20 August 2026.

These calculators are not veterinary advice

Every tool on this site estimates from population averages published in veterinary research. A calculator cannot examine your puppy, weigh it, feel its ribs, read its bloodwork, or know its medical history. Nothing here diagnoses, treats, or prevents any condition.

Call a veterinarian if any of these apply

• Your puppy is losing weight, or has not gained weight in two weeks.
• Your puppy refuses food for more than 12 hours, or is vomiting repeatedly.
• Your puppy is lethargic, collapsing, or has pale gums.
• Your puppy has diarrhoea lasting more than 24 hours, or any blood in its stool.
• Your puppy has crossed downward through two or more centile lines on a growth chart.
• You are unsure. An unsure owner calling a vet is always the right call.

If you believe your puppy has eaten something toxic, contact your veterinarian or an animal poison control service immediately. Do not wait for a calculator.

We do not publish medication dosing tools

This site deliberately does not calculate drug doses. Dosing depends on the exact product concentration, your puppy's weight on the day, its organ function, and what else it is taking. A wrong number could seriously harm a small puppy. Dosing is a conversation with your veterinarian.

Accuracy and limits

We cite the source for every formula and state on each page where that method stops being reliable. Estimates are presented as ranges because that is what the underlying data supports. Real puppies vary. Genetics, nutrition, neuter status, and health all shift outcomes away from a population average.

No liability

This site is provided as is, without warranty of any kind. To the fullest extent permitted by law, we accept no liability for any loss or harm arising from use of, or reliance on, the information or calculators here. You use them at your own discretion.

Not affiliated with any organisation or brand

We are independent. We are not affiliated with, endorsed by, or sponsored by the American Kennel Club, WALTHAM, Mars Petcare, Purina, Royal Canin, Banfield Pet Hospital, or any other organisation named on this site. Where we describe a method popularised by an organisation, we say so and cite the original publication.

Questions

Found a number you think is wrong? Tell us and we will check it against the source and correct it. See our editorial standards for how corrections are handled, and our sources page for the full bibliography.