Pet fish

Fish lifespan calculator

A betta, goldfish, tetra and koi should not share one lifespan number. This calculator uses fish group and age for the range, while tank answers shape the notes.

Reviewed: 2026-09-23

Lifespan range

2-35 years

Estimated lifespan

Remaining years together

Model

fish-lifespan-v0.1

Colorful pet fish swimming in a planted home aquarium

Calculating does not save details. Saving is optional and creates a link anyone with the link can read.

Name (optional) Age in years Country or region Fish group Water type Tank or pond setup Water quality checks Filtration Temperature Stocking and compatibility Feeding pattern New-fish quarantine Known health signs

This estimate is for planning, not a medical prognosis. Fish group and age change the lifespan number; water, tank and health fields shape the notes.

For planning and education only. It does not replace an aquatic veterinarian or qualified fish-health advice. Seek help for gasping, clamped fins, spots, wounds, bloating, swimming changes or sudden losses.