The Gray Muzzle Ledger / Dog years calculator: dog age in human years

Dog years calculator: dog age in human years

Quick answerResearchers at UC San Diego and UC Davis found that human age ≈ 16 × ln(dog age) + 31, built from DNA changes in 104 Labrador Retrievers. The old “multiply by 7” rule does not match how dogs age.

Published Oct 19, 2026 · Updated Oct 19, 2026 · By the Editorial team. General education, not veterinary advice and not yet individually reviewed by a licensed veterinarian. About and sources

Try the calculator

Log how they are really doingWrite Daily Notes in PawLine, free for 30 days, and bring them to the vet.Every good day, on the record. Free to download. Try it free, no payment info needed, then decide after the trial.What is PawLine? An AI-powered pet health app whose answers draw on published veterinary research, including sources like PubMed. Ask health questions any hour, get emergency triage and first-aid steps, set medication reminders, keep a profile and daily notes for each pet and email them to your vet, and find nearby vets. Try it free for 30 days with no payment info needed; after the trial, continued access is an in-app purchase (weekly or yearly). Guidance only, not a diagnosis.

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Log how they are really doing

Write Daily Notes in PawLine, free for 30 days, and bring them to the vet.

Download on theApp Store Get it onGoogle Play

Complete pet profilesBreed, age, weight, health conditions and photos for each pet, so advice fits that animal.
Daily health notesWrite down symptoms and observations, then share the records with your vet by email.
Medication remindersSet medication schedules for every pet, get push notifications, and track dosing history.

Every good day, on the record. Free to download. Try it free, no payment info needed, then decide after the trial.

What is PawLine? An AI-powered pet health app whose answers draw on published veterinary research, including sources like PubMed: instant health answers, emergency triage with first-aid steps, medication reminders, pet profiles and daily notes you can email to your vet, and nearby vet search. The 30-day free trial needs no payment info; after it, continued access is an in-app purchase, weekly or yearly (see the store listing). PawLine gives guidance and information, not a diagnosis. Always consult a licensed veterinarian for medical decisions.

How it works

The formula comes from DNA methylation patterns in Labrador Retrievers aged 4 weeks to 16 years, compared with humans. “ln” is the natural logarithm.

It is one breed, and breeds age differently. Small dogs tend to live longer than large dogs, so your dog may be older or younger than the number shows.

Every good day, on the record. Get PawLine on the App Store · Get it on Google Play

What it does not tell you

It does not tell you your dog’s health. A number cannot replace checkups. Senior dogs benefit from regular exams, and your vet decides what is right for your dog.

Frequently asked questions

Is the ×7 rule right?

No. The UC Davis health page says researchers found a different relationship from DNA methylation, human age = 16 ln(dog age) + 31. It is built on Labradors only, so use it as a rough guide.

Does a large dog age faster?

The UC Davis page notes that small dogs tend to live longer than large dogs, and the study covered one breed. Ask your vet about your dog.

Keep your senior pet’s whole story in your pocket

PawLine keeps a health profile, daily notes and medication schedule for each pet, and lets you email the records to your vet.

Download on theApp Store Get it onGoogle Play

Complete pet profilesBreed, age, weight, health conditions and photos for each pet, so advice fits that animal.
Daily health notesWrite down symptoms and observations, then share the records with your vet by email.
Medication remindersSet medication schedules for every pet, get push notifications, and track dosing history.
Instant health answersAsk about a symptom, diet or behavior question and get a research-backed answer, day or night.
Emergency triageHelps you judge whether your pet needs urgent veterinary care, with step-by-step first aid while you get to the vet.
Nearby vets and pet placesFind vet clinics, dog parks, groomers and pet shops, and save favorites.
Birthday remindersA reminder before each birthday with breed facts.
Many speciesDogs, cats, birds, rabbits, reptiles, small pets, and livestock such as horses, goats, sheep, cows and chickens.

Every good day, on the record. Free to download. Try it free, no payment info needed, then decide after the trial.

Sources

UC Davis: Calculating your dog’s age https://healthtopics.vetmed.ucdavis.edu/health-topics/canine/calculating-your-dogs-age
2023 AAHA Senior Care Guidelines for Dogs and Cats (PDF) https://www.aaha.org/wp-content/uploads/globalassets/02-guidelines/2023-aaha-senior-care-guidelines-for-dogs-and-cats/resources/2023-aaha-senior-care-guidelines-for-dogs-and-cats.pdf

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Good days: a quality of life self-check for older petsA gentle seven-category scale (HHHHHMM, by Dr. Alice Villalobos) to notice changes and bring notes to your vet.When is a dog or cat considered senior?What “senior” means in the AAHA guidelines: the last 25% of a dog’s expected lifespan, and over 10 years for cats.How often should a senior pet see the vet?AAHA recommends a senior workup once or twice a year, with lab work every 6 to 12 months. What to ask and bring.Signs of pain and arthritis in older dogs and catsSlowing down is not just age. Mobility changes to write down and show your vet, including how cats hide arthritis.