Two flocks can eat similar amounts of feed and reach very different market weights — the difference usually comes down to feed conversion ratio (FCR) and how well mortality is controlled. This calculator turns your raw production numbers into the two figures that actually predict profitability: average daily weight gain and FCR.
Average Daily Gain (ADG) = (Final Weight − Initial Weight) ÷ Rearing Period (days), given in grams per bird per day. FCR = Total Feed Consumed per Bird ÷ Live Weight Gained per Bird. A lower FCR means less feed was needed per kilogram of weight put on — it is the single most watched number in commercial broiler production.
| Age (days) | Target Live Weight | Target FCR |
|---|---|---|
| 28 | 1.1-1.3 kg | 1.35-1.45 |
| 35 | 1.6-1.9 kg | 1.55-1.65 |
| 42 | 2.1-2.4 kg | 1.65-1.80 |
| 49 | 2.6-2.9 kg | 1.85-2.00 |
A flock of 1,000 birds starts at 42 g and reaches 2.3 kg live weight after 42 days, having eaten 3.9 kg of feed per bird, with 30 birds lost to mortality. ADG = (2,300 − 42) ÷ 42 ≈ 53.8 g/day. FCR = 3.9 ÷ 2.258 (adjusted gain) ≈ 1.73 — a solid result close to the 42-day benchmark above. If your FCR comes out above 1.9 at this age, check ventilation, water availability, and disease pressure before assuming the feed itself is the problem.
Under typical open-shed conditions, an FCR of 1.7-1.9 at 42 days is considered good. Controlled-environment houses with tunnel ventilation can achieve 1.55-1.65 at the same age.
High FCR with visibly healthy birds usually points to feed wastage from poorly adjusted feeders, water leaks that lead to wet, spoiled feed, or a feed formulation that's slightly under-specified in energy or amino acids.
Yes. Feed consumed by birds that later die is a real cost but doesn't show up in final live weight, so high mortality artificially inflates FCR. This calculator lets you enter mortality count so the result reflects your actual flock performance.
Weekly is standard practice — weigh a representative sample of 20-30 birds and log cumulative feed used. Catching a rising FCR trend at week 3 gives you time to intervene before the whole cycle is affected.