Dog Age Calculator

Convert dog years to human years

Choose a breed (or size) and enter an age to convert between dog and human years.

Last updated: January 11, 2026

CreatorFrank Zhao

Breed

More info

Dog age

More info

Human age

More info

Scientific Insight

Labrador aging follows a specialized logarithmic curve based on recent epigenetic research. Check out our detailed science section below to learn more.

1Other breeds (table interpolation)

human\_years = get\_human\_years(dog\_years,\;size)

2Labrador

human\_age\_{labr} = 16\,\ln(dog\_age\_{labr}) + 31

dog_yearsDog age (Other)

human_yearsHuman age (Other)

sizeSmall/Medium/Large

dog_age_labrDog age (Labrador)

human_age_labrHuman age (Labrador)

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Introduction / Overview

The Dog Age Calculator helps you translate a dog’s age into a human-equivalent age (and back again) using two approaches: a breed-specific model for Labradors, and a size-based table for other dogs.

What problem does it solve?

It replaces the oversimplified “dog years × 7” idea with conversions that better reflect how dogs age in early years versus later years.

Who is it for?

Pet owners, adopters, vets and vet techs (for quick context), shelters, and anyone trying to compare “life stages” across species.

✅ Reliability note: the Labrador option uses a published logarithmic model, while the “Other” option uses a size-adjusted table with linear interpolation.

If you’re also thinking about life stages, you may like our Dog Life Expectancy Calculator as a companion tool.

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How to Use / Quick Start Guide

Choose a breed: Labrador for the published logarithmic model, or Other to use the size-based table.
If you pick Other, choose a size (Small / Medium / Large).
Type a value into either “Dog age” or “Human age”. The other field updates automatically.
If you see a warning, it usually means the computed value is outside the supported range (for example, beyond the table).

Example A (Labrador): dog age → human age

Suppose your Labrador is $d = 5$ years old. The calculator uses:

h = 16\,\ln(d) + 31

h

=

16\,\ln(5) + 31

\approx

56.8

In plain language: a 5-year-old Labrador maps to roughly 57 human years under this model.

Example B (Other, Medium): dog age with half-year → human age

Suppose you select Other + Medium and enter $d = 5.5$ . The calculator interpolates between the table values at $d = 5$ and $d = 6$ .

h

=

36 + 0.5\,(42 - 36)

=

39

So $5.5$ dog years corresponds to about 39 human years for a medium-sized dog.

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Real-World Examples / Use Cases

1) Adoption paperwork “age guess”

Background: a rescue lists a dog as “about 2 years old” and you want to sanity-check what that means in human terms.

Input: $d = 2$ (Other + any size).

Output (table for early years): $h \approx 24$ .

How to use it: helps you compare “life stage” (young adult vs fully mature) when planning training and routines.

2) Senior care planning

Background: your dog is slowing down and you want a rough human-age context for checkup cadence.

Input: Other + Large, $d = 10$ .

Output (table): $h \approx 66$ .

How to use it: discuss senior-screening schedules with your veterinarian.

3) Labrador-specific curiosity

Background: you have a Labrador and you’re curious how the published epigenetic model maps its age.

Input: Labrador, $d = 3$ .

h

=

16\,\ln(3) + 31

\approx

48.6

How to use it: treat it as a scientific reference point, not a clinical diagnosis.

4) Lifestyle + long-term planning

Background: you’re planning diet and activity adjustments as your dog ages.

Tip: after you estimate a human-equivalent age, pair it with a longevity context using our Dog Life Expectancy Calculator.

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Common Scenarios / When to Use

Especially useful when…

Comparing a dog’s “life stage” to a human age range.
Explaining aging to kids or family members in simple terms.
Doing a quick sanity check on a rescue’s estimated age.

It may be less suitable when…

The dog’s age is far outside the supported table range.
You need clinical guidance (this is not medical advice).

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Tips & Best Practices

🧠

Don’t overthink decimals. Half-years are totally fine. The calculator interpolates smoothly.

If you enter $d = 5.25$ you’ll get a result between the $d = 5$ and $d = 6$ table values.

Common mistakes to avoid

Mixing up “Labrador” vs “Other”. If your dog is a mixed breed, “Other” is usually the safer choice.
Ignoring warnings: they often mean the computed age is outside the model’s supported range.

For best accuracy

Use known age (birth date or vet estimate) rather than “looks like”.
Choose size based on adult weight category if the dog is still growing.

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Calculation Method / Formula Explanation

Labrador model (logarithmic)

When you choose Labrador, the calculator uses a logarithmic relationship between dog age $d$ and human age $h$ :

h = 16\,\ln(d) + 31

Here $\ln$ is the natural logarithm.

🔬

Labrador research is here!

Dog aging isn’t just a fun internet debate — it’s an active research topic. A published study used epigenetic markers (DNA methylation patterns) from a cohort of Labradors to build a quantitative mapping from dog age to human-equivalent age. That’s where the Labrador formula in this calculator comes from.

If you’re curious, the original paper is available here: Quantitative translation of dog-to-human aging by conserved remodeling of epigenetic networks.

h

=

16\,\ln(d) + 31

Practical takeaway: this model is Labrador-specific; for other breeds we use size-based table interpolation instead.

Other breeds (table + interpolation)

For Other breeds, the calculator looks up human-age values from a size-based table and interpolates between integer years. If the dog age is $d = n + f$ where $n$ is an integer and $0 \le f \le 1$ , then:

h(d)

=

h(n) + f\,\bigl(h(n+1)-h(n)\bigr)

Where $h(n)$ is the table value for an integer dog age $n$ at the chosen size.

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Related Concepts / Background Info

Why “×7” isn’t great

Dogs age very fast in the first couple of years and then slow down. A single constant multiplier can’t capture that curve. That’s why models often use either a non-linear function (like $\ln$ ) or empirically derived tables.

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Frequently Asked Questions (FAQs)

Is this medical advice?

No. It’s a conversion tool for context. If you have health concerns, a veterinarian is the right person to talk to.

Why does size matter for “Other” breeds?

Different size categories tend to have different aging profiles. The calculator approximates this by selecting a size-specific table.

Can I enter half-years or decimals?

Yes. For “Other” breeds the calculator uses linear interpolation. If $d = n + f$ , it computes $h(d) = h(n) + f\,(h(n+1)-h(n))$ .

Why do I see a warning after reverse calculation?

If you type a very large human age, the reverse-mapped dog age might fall outside the supported range. The warning is there so you don’t accidentally interpret an out-of-range result as “precise”.

What if my dog is a Labrador mix?

If you’re not sure, try “Other” first. Think of “Labrador” mode as a breed-specific model rather than a universal rule.

⚠️

Limitations / Disclaimers

This calculator is for educational purposes only. It does not replace veterinary advice, diagnosis, or treatment.

Breed, genetics, health history, and lifestyle can shift real-world aging patterns.
Out-of-range values may produce warnings or no result.

🔗

External References / Sources

Labrador logarithmic mapping (2019 research paper): Semantic Scholar link

Data for the “Other” mode is implemented as a size-based lookup table with linear interpolation.

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