Feed Conversion Ratio (FCR) Calculator

What Is Feed Conversion Ratio (FCR)? Feed conversion ratio (FCR) = feed consumed (kg) / weight gained (kg). A lower FCR is better, because it means less feed is needed per kg of animal product. Also called feed conversion efficiency (FCE), which is the inverse: FCE = weight gain / feed consumed. FCR is one of the most important metrics in commercial livestock production.

Typical FCR Values Broiler chickens: 1.6-2.0 (best: under 1.6 in optimized commercial flocks) Turkeys: 2.0-2.8 Pigs (swine): 2.5-3.5 Farmed salmon: 1.0-1.5, because a cold-blooded animal spends nothing on body heat Tilapia: 1.5-2.0 Beef cattle (feedlot): 6.0-8.0 Sheep: 4.0-6.0 Rabbits: 3.0-4.0

Dairy cattle are deliberately absent from the calculator’s list. Dairy efficiency is measured as milk out per kg of dry matter in, not weight gain, so an FCR calculated the way this page does it would not mean anything for a milking herd.

Why Fish Are More Efficient Fish are cold-blooded (ectothermic), so they don’t spend energy maintaining body temperature. This is why aquaculture FCRs are much lower than cattle or poultry. A broiler chicken must eat ~2 kg of feed to gain 1 kg of body weight. A salmon only needs ~1.2 kg of feed for 1 kg of body weight.

Factors Affecting FCR Animal genetics: modern breeds are selected for low FCR. Feed quality: higher protein/energy density improves FCR. Age: younger animals grow faster with better FCR. Health: sick animals convert feed poorly. Environment: temperature, space, and stress affect FCR. Management: feeding frequency, water quality (aquaculture), housing type.

Economic Impact Feed costs typically represent 60 to 70% of livestock production costs. Take a broiler flock of 50,000 birds grown to about 2.5 kg, so roughly 2.4 kg of gain each and 120 tonnes of gain across the flock. At FCR 2.0 that flock eats 240 tonnes of feed; at 1.8 it eats 216. The 0.2 improvement saves 24 tonnes per cycle, and at six or seven cycles a year that is 150 tonnes off the annual feed bill from one flock house. The arithmetic is simply gain × the change in FCR, which is why the saving scales with how much weight you are putting on rather than with how many animals you have. For a cattle feedlot, each 0.1 improvement in FCR can save thousands per cycle.

Calculating Total Feed Cost Total feed cost = FCR × target weight gain × feed price per kg. Feed needed = FCR × weight gain × number of animals. Days to market = target weight / average daily gain.

Sustainability Lower FCR = less land for feed crops, less water, lower greenhouse gas emissions. Beef has the highest environmental footprint per kg of protein (high FCR + ruminant methane). Moving protein production toward fish, insects, and poultry reduces environmental impact.