Broiler feed calculator

How does the calculator work?

• Feed per bird: the Ross 308 table gives the total feed one living bird eats from day 0 to each day of age. For example, 3,211 g to day 35.
• Flock feed (kg) = chicks placed × feed per bird (g) ÷ 1,000 × (1 + extra % ÷ 100).
• Stages: starter from day 0 to 10, grower from day 11 to 24 and finisher from day 25, as set out in the Ross Broiler Pocket Guide. Feed for a stage = total feed to the last day of the stage minus total feed to the day before it starts.
• Bags = stage feed ÷ bag size, rounded up to whole bags for each stage, because feed is bought by the bag.
• FCR = feed used (kg) ÷ live weight sold (kg), where feed used = (bags delivered − bags left) × bag size.

Worked example

A farmer places 1,000 chicks, plans to sell at day 35, buys 50 kg bags and adds 5% for waste.

For FCR: the same farmer had 70 bags delivered and 2 left over, so the flock used 68 × 50 = 3,400 kg of feed. The birds sold for 2,150 kg live weight. FCR = 3,400 ÷ 2,150 = 1.58. The Ross 308 target at day 35 is 3,211 ÷ 2,296 = 1.40. At the target FCR, 2,150 kg of bird would need about 1.399 × 2,150 = 3,008 kg of feed, so this flock used about 392 kg more. Our guide on how to reduce FCR in broilers shows where that feed usually goes.

Ross 308 targets used by the calculator

These are the as-hatched (mixed male and female) figures from Aviagen’s Ross 308 Performance Objectives 2022. Feed is per living bird. The calculator uses the full day-by-day table from day 1 to day 56; this is a weekly summary.

Aviagen notes that the table values are rounded, so small differences can appear when you calculate from them. Stage timing is from the Ross Broiler Pocket Guide (Aviagen, 2025).

What are the limits of this calculator?

• Targets, not a promise. Aviagen says these figures are achievable under good management, good conditions and recommended nutrient levels, and that average farm results may be lower. In a hot summer, most open-sided sheds eat more feed for each kilogram of gain.
• One breed. The numbers are for Ross 308. Cobb, Hubbard and other breeds have their own tables, so use your breed’s guide if you raise another bird.
• Birds placed, not birds alive. The table is feed per living bird, but the calculator multiplies by chicks placed. If some birds die, the real need is a little lower, which acts as a small safety margin.
• Farm FCR reads higher. Your FCR includes feed eaten by birds that later died and feed spilled on the litter. The Ross FCR counts living birds only and includes the chick’s starting weight.
• Your programme may differ. The pocket guide allows starter up to day 14 if birds are behind target weight. Follow the stage timing your feed supplier and your vet set for your flock.
• No prices. Feed rates change with the market, so this tool works in kilograms and bags only.

Weigh a sample of birds every week and compare them with our broiler weight chart. For the day-by-day intake and how feeders affect it, read how much feed a broiler eats. If birds look sick, call your vet before you change the feed.

Prepared by Waqas Rafiq, CEO, Vital Feeds (Private) Limited. Figures checked by hand against the Aviagen table on 5 October 2026.

See how our broiler starter, grower and finisher feed is staged, or contact the mill (UAN 0311 1555136) to plan feed deliveries for your next flock.