Cat Age Calculator
Convert your cat’s age to human years. Free calculator with life stages, weight check, and care guidance for indoor and outdoor cats.
Cat Age Calculator
years
How Cat Age Calculation Works
- First year ≈ 15 human years
- Second year ≈ 9 human years
- Each year after ≈ 4 human years
This cat age calculator converts your cat's age to human years and shows life stages (kitten, adult, mature, senior, geriatric). Optional weight and lifestyle inputs help you see life expectancy and simple health guidance. Free cat years to human years converter.
How to Use Cat Age Calculator
How to enter your cat's age
Type your cat's age in years (e.g. 7 or 7.5). Use decimals for months (e.g. 0.5 for 6 months). The cat age calculator supports ages from 0 to about 25 years.
Select lifestyle
Choose Indoor Only, Outdoor Only, or Indoor/Outdoor. Lifestyle affects typical life expectancy: indoor cats often live longer than outdoor cats.
Optional: breed and weight
You can optionally select a breed and enter weight (lbs or kg). If you enter weight, the tool compares it to a rough ideal range for that breed and shows a simple health risk level (average, moderate, or high).
What to do with your results
See human age equivalent, life stage, life expectancy, and—if weight was entered—a brief weight/health risk note. Use this to plan vet visits and discuss diet with your vet.
Calculator Features
Cat years to human years
Converts cat age using a common formula: first year ≈ 15 human years, second ≈ 9, then about 4 human years per cat year.
Life stages
Shows kitten/young adult, adult, mature adult, senior, or geriatric so you can adjust care and watch for age-related changes.
Lifestyle and life expectancy
Indoor, outdoor, or mixed lifestyle is used to give a simple life expectancy range (e.g. 13–17 years for indoor).
Optional weight check
If you enter weight and breed, the tool compares to approximate ideal weight and gives a simple risk level (average, moderate, high) to discuss with your vet.
Complete Function List
- Cat age to human years conversion:
- Life stage (Kitten, Adult, Mature, Senior, Geriatric):
- Lifestyle: indoor, outdoor, or both
- Life expectancy ranges by lifestyle:
- Optional breed selection:
- Optional weight in lbs or kg with unit toggle:
- Simple weight-based health risk (average/moderate/high):
- Breed-specific ideal weight reference:
- Free, no account needed:
Common Calculations & Examples
Example 1: 7-year-old indoor cat
Problem: You have a 7-year-old indoor cat and want to convert their age to human years and see life stage.
Steps:
- Enter 7 in the cat's age field
- Select Indoor Only
- View results
Explanation: First 2 cat years = 24 human years; 5 more years × 4 = 20, so 24 + 20 = 44. Indoor cats often live into their teens.
Example 2: 1-year-old kitten
Problem: Your kitten just turned 1. How old is that in human years?
Steps:
- Enter 1 in the cat's age field
- Select the lifestyle you plan (e.g. Indoor Only)
- View results
Explanation: The first year is commonly treated as about 15 human years in cat age formulas.
Example 3: Senior cat with weight check
Problem: Your 12-year-old cat weighs 14 lbs and you want human age plus a rough weight assessment.
Steps:
- Enter 12 in the cat's age field
- Select lifestyle
- Select breed if known (e.g. Mixed)
- Enter 14 and choose lbs
- View results
Explanation: Weight is compared to a breed-based ideal; being far above or below can increase health risks, so vet guidance is important.