Pets

Fish Feeding Calculator

Built by Kevin Glover · @gloverbuilds · Verified formula

Calculate how much to feed your fish. Portion size by fish count and type. Free feeding calculator.

📅 Updated April 2026 ✅ Formula verified 📖 4 min read 🆓 Free · No sign-up

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The 2-Minute Rule

Feed only what your fish consume within 2 minutes. Anything remaining after 2 minutes is overfeeding. Remove uneaten food immediately — it decomposes, produces ammonia, and degrades water quality. Overfeeding is the single most common cause of fish death in home aquariums, killing more fish than disease or equipment failure.

Feeding Frequency by Fish Type

Most tropical fish: 1-2 times per day. Goldfish: 2-3 small feedings per day (no stomachs — frequent small meals). Bettas: Once daily, skip one day per week (mimics natural fasting). Bottom feeders (corys, plecos): Sinking wafers at night when other fish are inactive. Variety matters — alternate between flakes, pellets, frozen, and live foods for balanced nutrition.

⚡ CalcWolf Insight

Overfeeding is the #1 killer in home aquariums — more than disease or equipment failure. Uneaten food decomposes into ammonia, poisoning the tank. Most fish need far less food than owners provide.

Frequently asked questions

How much should I feed my fish?▾

A pinch that disappears within 2 minutes, once or twice daily. Fish stomachs are roughly the size of their eye — they need far less food than most owners provide. A fish can survive 1-2 weeks without food; it cannot survive a week of overfeeding.

What happens if I overfeed my fish?▾

Uneaten food decomposes, producing ammonia and nitrite — both toxic. Water turns cloudy, beneficial bacteria are overwhelmed, and fish develop stress, disease, and die. If you can see leftover food on the bottom 5 minutes after feeding, you are feeding too much. Cut the amount in half.

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Kevin Glover · @gloverbuilds

Founder, CalcWolf · GLVTS · Blickr

All formulas sourced from primary references — IRS publications, peer-reviewed research, and official standards. Results are tested against independent reference calculators before publishing. Rates and brackets updated when official sources change. Editorial policy →