Small Mammal
Rat age in human years
Enter your Rat's age to see its human-year equivalent, life stage, and lifespan.
Frequently asked questions
How old is a Rat in human years?+
Enter your Rat's age in the calculator above. We use a science-based formula for small mammals — not the old "multiply by seven" rule — and show life stage and lifespan context with your result.
What is the average lifespan of a Rat?+
Rats are often cited as living around 3 years on average. Individual animals vary with diet, genetics, and care.
How do I use this Rat age calculator?+
Pick Rat (already selected here), enter age in years or use date of birth when available, then calculate. You'll see human-year equivalent, life stage, and how far through a typical lifespan your pet may be.
Rat age chart
Swipe the table sideways to see all columns.
| Age | Human age | Life stage |
|---|---|---|
| 3 months | About 7 | Juvenile |
| 6 months | About 13 | Young Adult |
| 9 months | About 20 | Young Adult |
| 1 year | About 27 | Adult |
| 2 years | About 53 | Mature |
| 3 years | About 80 | Senior |
| 4 years | About 107 | Senior |
| 5 years | About 120 | Senior |
| 6 years | About 120 | Senior |
This chart is a general estimate. Real aging varies with genetics, weight, health, diet, and veterinary care.
Related
