Dog Age Calculator
Convert your dog's age to human years using the latest scientific formula. Enter your dog's age and select its size to get an accurate equivalent human age.
Published by:
isCalculator Editorial Team
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How to use this tool?
How to Use the Dog Age Calculator
- Enter your dog's age in years (e.g., 5). Use decimal values for partial years (e.g., 2.5).
- Select your dog's size from the dropdown:
- Small (≤ 20 lbs / 9 kg)
- Medium (21–50 lbs / 9.5–22.7 kg)
- Large (51–100 lbs / 23–45 kg)
- Giant (> 100 lbs / 45 kg)
- Click "Calculate Human Age".
- Your result shows the human age equivalent based on a scientific formula (16 × ln(dog age) + 31), adjusted for size.
Note: Dog age must be greater than 0. Use positive numbers only.
Previous Results
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Frequently Asked Questions
We use the formula: Human age = 16 * ln(dog age) + 31, which is based on DNA methylation changes. This is more accurate than the old '1 dog year = 7 human years' rule.
Different dog sizes age at different rates. Larger dogs tend to age faster, so we adjust the formula with a multiplier: small (0.95), medium (1.0), large (1.05), giant (1.1).
Yes, but the formula is most accurate for dogs over 1 year old. For puppies, the conversion is less precise because they mature rapidly.