Tool
Feed Conversion Ratio Calculator (FCR)
Calculate nowQuick answer
Feed conversion ratio is how many pounds of feed the group ate for each pound of weight it gained: FCR = feed used (lb) ÷ weight gained (lb). Gain is the total weight that left minus the total weight that came in, so animals that died take their starting weight out of the gain while the feed they ate stays in the numerator. That is why high mortality worsens FCR even when survivors do well. The lower the number, the more efficient the group.
Guide · $12The Quail Egg Production GuideThe formula
FCR = feed used by the group (lb) ÷ weight gained by the group (lb)
gain = (animals at the end × average ending weight) − (animals placed × average starting weight)
Written this way, the gain removes the weight the animals already had when they arrived and makes mortality visible: animals that died are counted in the starting weight but not in the ending weight, while the feed they ate stays in.
The Government of Alberta 4-H guide on feeding terms and feed cost calculations defines feed conversion efficiency as the pounds of feed needed to produce one pound of gain: 6.5:1 means 6.5 lb of ration per lb of gain.
Compare like with like
A ratio means something only next to a reference for the same species, genetics, age and system. Broilers, pigs and steers convert feed very differently.
What the number does not tell you
FCR flags that something changed: feed waste at the feeder, heat or cold stress, water quality, disease or a different ration. Finding out which one takes work in the barn.
Frequently asked questions
Does feed eaten by animals that died count?
Yes. The ratio measures how much feed the group used to produce the pounds that left. Feed eaten by an animal that died was spent and never became product, so mortality makes FCR worse.
What is a good feed conversion ratio?
It depends on species, genetics, age and system. As a sourced example, the Government of Alberta 4-H guide lists about 6:1 to 7:1 for finishing steers and 8:1 to 9:1 for growing steers.
Why subtract the starting weight?
Only the weight gained during the period was produced by that feed. Ignoring the starting weight makes FCR look better than it really is.
Can I use kilograms instead of pounds?
Yes. The ratio has no unit as long as feed and weight use the same one. Just ignore the lb labels on the daily figures.
Sources
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