Home›Tools›Dog Age Calculator

Dog Age Calculator
Dog Years to Human Years

Free, instant, and vet-formula based. No sign-up required.

✓ Epigenetic Formula✓ Breed Size Adjusted✓ Free & Instant

📅

Dog Age Calculator

Dog's Age (years, decimals OK)

Breed Size

🐩Small<20 lbs

🐕Medium20–50 lbs

🪶Large50–90 lbs

🐻Giant90+ lbs

—

Human Years Equivalent

—

% of avg lifespan

—

avg lifespan (yrs)

📖 How It Works

The Science Behind Dog Years

In 2019, UC San Diego researchers published a landmark epigenetic study revealing the accurate formula is human age = 16 × ln(dog age) + 31. Dogs age extremely rapidly in year one then slow considerably.

Our calculator applies this formula then adjusts for breed size — a 7-year-old Chihuahua and Great Dane are in completely different life stages.

🔮 Formula

human_age = 16 × ln(dog_age) + 31. Size offsets: Small −2 to −5 yrs. Large +2 to +5 yrs. Giant +5 to +12 yrs.

📊 Reference Chart

Dog Years by Size

Dog Age	🐩 Small	🐕 Medium	🪶 Large	🐻 Giant
1 yr	15	15	15	15
2 yrs	24	26	27	29
3 yrs	28	31	33	36
5 yrs	36	40	43	50
7 yrs	44	50	55	63
10 yrs	56	62	68	79

🐾 Life Stages

Dog Life Stages & Care Tips

🐕 Puppy (0–1 yr)

Rapid growth, vaccinations, socialization. Feed puppy-formula food. Gentle exercise only.

🐕 Junior (1–2 yrs)

Reaching maturity. Transition to adult food at 12–18 months. Discuss spay/neuter with vet.

🪶 Adult (2–7 yrs)

Peak health. Annual vet visits, dental cleanings every 1–2 years, calibrated calories.

⚕️ Senior (7+ yrs)

Vet every 6 months. Watch for joint issues and cognitive changes. Consider senior food.

❓ FAQs

Dog Age FAQs

Use the 2019 UC San Diego formula: human age = 16 × ln(dog age) + 31. Also apply a breed size offset. Large dogs age faster than small dogs after maturity.

No. A 1-year-old dog is sexually mature — no 7-year-old human is. Dogs age roughly 15 human years in their first year, then slow considerably.

Small dogs: 10–11 years. Medium: 8–9 years. Large: 7–8 years. Giant breeds: 5–6 years. The AVMA recommends vet visits every 6 months once senior.

Small ≈ 24. Medium ≈ 26. Large ≈ 27. Giant ≈ 29 human years. All fully mature young adults.

🧮 More Tools