Fish Feeding Calculator
Calculate the correct fish food amount by fish type and tank size.
Returns daily portion in grams to avoid overfeeding goldfish, tropical, and marine species.
Proper fish feeding prevents overfeeding — the single most common cause of aquarium water quality problems, ammonia spikes, and fish death.
The 2-minute rule: Feed only what your fish can consume within 2–3 minutes. Remove any uneaten food immediately after that window closes. Decomposing food drives up ammonia and nitrite, which are toxic even at low concentrations.
Daily feeding amount by body weight:
Daily Feed = Body Weight × 2–3%
- Small fish (~1 inch / 2.5 cm): roughly 1–2 pellets per fish per feeding
- Medium fish (~3 inches / 7.5 cm): roughly 3–5 pellets per fish per feeding
- Large fish (~6+ inches / 15+ cm): roughly 8–12 pellets per fish per feeding
Feeding frequency by species:
- Tropical community fish: 1–2 times daily
- Goldfish: 1–2 times daily (small amounts; they have no stomach)
- Bettas: Once daily (skip one day per week to prevent bloat)
- Cichlids: 2–3 times daily
- Bottom feeders (corydoras, plecos): Once daily at night (they are nocturnal)
- Fry (baby fish): 3–5 times daily in tiny amounts to support fast growth
Worked example: You have 10 neon tetras, each weighing about 0.5 g. Total daily feed ≈ 10 × 0.5 g × 2.5% = 0.125 g — a tiny pinch. Split across two feedings: roughly a few flakes each time.
Warning signs of overfeeding:
- Cloudy, milky water within hours of feeding
- Algae blooms (excess nutrients fuel algae)
- Ammonia or nitrite readings above 0 ppm
- Uneaten food visible on the substrate after 5 minutes
Tip: Healthy fish behave slightly hungry. If they dart to the surface eagerly at feeding time, you are feeding correctly.