Quick Answer

Use the calculator below to find your fish's age in human years. The old "multiply by 7" rule is inaccurate — aging varies by size and breed.

Fish Age Calculator

How Old Is My Fish in Human Years?

Fish lifespans vary enormously. Bettas live 3-5 years; Goldfish can live 20+ years with proper care.

Average Fish Lifespan

Varies by species

With proper care, many fishs exceed this average.

⏰

3-20+ yrs

Lifespan range

🐟

Betta

3-5 years

🐠

Goldfish

10-20 years

🎏

Koi

25-35 years

📊 Fish to Human Age Conversion Chart

Fish Age	Human Equivalent	Life Stage
1 year	~5 human years	Young (varies)
3 years	~15 human years	Adult
10 years	~40 human years	Mature
20 years	~70 human years	Senior

🐾 Fish Life Stages

Fry

0-2 months

Newly hatched, vulnerable.

Juvenile

2-6 months

Growing, developing coloration.

Adult

6 months+

Full size, breeding age.

Senior

Species-dependent

Slower, may fade in color.

💚 How to Help Your Fish Live Longer

Proper Tank Size

Bigger is better. Goldfish need 20+ gallons each.

Water Quality

Weekly water changes, proper filtration.

Correct Temperature

Species-appropriate heating. Stability matters.

Low Stress

Compatible tankmates, hiding spots.

Quality Food

Varied diet, don't overfeed.

Lifespan by Fish Breed

Different breeds have different lifespans. Click for breed-specific aging info.

Betta Fish3-5 years Goldfish10-20 years Guppy2-3 years Neon Tetra5-10 years Angelfish10-15 years Clownfish6-10 years Oscar Fish10-20 years Corydoras Catfish5-10 years Molly Fish3-5 years Platy Fish3-5 years

Frequently Asked Questions

How long do goldfish really live?▼

With proper care in 20+ gallon tanks: 10-20 years. Carnival goldfish die quickly due to bowl conditions, not inherent fragility.

Why do bettas seem to die young?▼

Poor pet store conditions, tiny tanks, and lack of heaters. Properly kept bettas live 3-5 years.

What's the oldest fish ever?▼

Hanako, a koi in Japan, lived an estimated 226 years. Typical koi live 25-35 years.

Track Your Fish's Health Journey

Get age-appropriate care reminders, vet schedules, and health tracking for your fish.

Start Tracking Free →Browse Fish Breeds

Trusted sources: AVMA Pet Care · UC San Diego Aging Study