How Big Will My Cat Get Calculator
Predict your kitten's adult size and weight based on current age and development
Predict Your Cat's Adult Size
Age should be between 4-52 weeks for best accuracy
Weigh your kitten accurately for best prediction
Select the closest breed type to improve accuracy
Size Prediction Results
Enter your kitten's age and weight to predict adult size
📊 Kitten Growth Guidelines
4-8 weeks: Rapid weight gain, doubling every 1-2 weeks
8-16 weeks: Steady growth, reaching 50% of adult weight by 16 weeks
4-6 months: Growth slows, sexual maturity begins
6-12 months: Final growth phase, approaching adult size
12+ months: Adult size reached for most breeds
💡 Large breeds like Maine Coons may continue growing until 2-3 years old
Average Adult Weights by Breed Type
| Breed Category | Examples | Weight Range (kg) | Weight Range (lbs) |
|---|---|---|---|
| Small Breeds | Singapura, Munchkin, Devon Rex | 2.5 - 4.0 | 5.5 - 8.8 |
| Medium Breeds | American Shorthair, British Shorthair | 3.5 - 5.5 | 7.7 - 12.1 |
| Large Breeds | Maine Coon, Ragdoll, Siberian | 4.5 - 8.0 | 9.9 - 17.6 |
| Siamese/Oriental | Siamese, Oriental Shorthair | 3.0 - 5.0 | 6.6 - 11.0 |
| Persian/Exotic | Persian, Exotic Shorthair | 3.5 - 6.0 | 7.7 - 13.2 |
💡 Male cats are typically 1-2 kg heavier than females of the same breed
Example Calculation
12-Week-Old Mixed Breed Kitten
Current Age: 12 weeks old
Current Weight: 1.2 kg (2.6 lbs)
Breed Type: Mixed breed (domestic shorthair)
Gender: Female (estimated)
Calculation Results
Formula: (1.2 kg ÷ 12 weeks) × 32 × 1.0 = 3.2 kg
Predicted Adult Weight: 3.2 kg (7.1 lbs)
Current Progress: 37.5% of adult weight
Time to Adult Size: Approximately 8-10 months
Assessment: Normal growth trajectory for mixed breed
Kitten Growth Stages
Neonatal (0-2 weeks)
Eyes closed, dependent on mother
Birth weight: 85-115g
Transitional (2-4 weeks)
Eyes open, beginning to walk
Weight doubles by 2 weeks
Socialization (4-12 weeks)
Learning social behaviors
Rapid weight gain period
Juvenile (3-6 months)
Sexual maturity approaches
Growth rate slows
Growth Tips
Nutrition: High-quality kitten food until 1 year old
Feeding: Multiple small meals throughout the day
Exercise: Encourage play to support healthy development
Monitoring: Weekly weigh-ins during rapid growth
Spay/Neuter: May affect final size if done before maturity
Understanding Kitten Growth and Size Prediction
How the Formula Works
The size prediction formula is based on the principle that kittens follow a predictable growth pattern during their first 32 weeks of life. The formula calculates the growth rate and projects it to estimate adult size.
Key Growth Facts
- •Kittens reach 50% of adult weight by 16 weeks
- •Growth slows significantly after 6 months
- •Most cats reach adult size by 12 months
- •Large breeds may grow until 2-3 years old
Prediction Formula
Final Size = (Weight ÷ Age) × 32 × Breed Factor
- Weight: Current weight in kg
- Age: Current age in weeks
- 32: Growth constant (weeks to maturity)
- Breed Factor: Adjustment for breed size (0.8-1.3)
Note: This prediction is most accurate for kittens aged 8-20 weeks. Individual variations, genetics, and nutrition can affect final size.