Feed is usually 60–70% of the total cost of growing fish. The Feed Conversion Ratio (FCR) tells you how efficiently your fish turn that feed into saleable weight. A lower FCR means less feed per kilogram of fish — and more profit.
How to calculate FCR
The formula is simple:
FCR = Total feed given ÷ Total fish weight gained
Weight gained is harvest biomass minus stocking biomass. For example, if you fed 180 kg of pellets and your fish grew from 50 kg to 150 kg (a gain of 100 kg):
FCR = 180 ÷ 100 = 1.8
That means it took 1.8 kg of feed to produce 1 kg of fish.
Calculate your FCR and feed cost (free) →
What is a good FCR?
- 1.0 – 1.4 — Excellent. Efficient feeding and good water quality.
- 1.4 – 1.8 — Normal range for many tilapia and catfish farms on pellet feed.
- Above 1.8 — A warning sign: overfeeding, wasted feed, poor water quality, or disease.
Target values vary by species, feed quality, and system. Track your own FCR each cycle and compare it to your own history — that trend matters more than any single benchmark.
How to improve (lower) your FCR
- Don't overfeed. Feed to appetite in small portions; remove uneaten feed habits. Overfeeding both wastes money and fouls the water.
- Keep water quality good. Stressed fish eat and convert poorly. Watch oxygen and ammonia (see our ammonia calculator).
- Use quality feed with the right protein and pellet size for the fish's age.
- Grade and stock sensibly. Overcrowding raises stress and lowers conversion (see the stocking density calculator).
- Keep fish healthy. Disease quietly wrecks FCR before you see deaths.
FCR and your profit
Because feed dominates cost, a drop from FCR 1.8 to 1.5 is real money. Once you know your FCR, feed price, and fish price, you can work out cost per kilogram and break-even. Our fish farm profit calculator puts those together.