Calculate how much feed your chickens need per day, week, and month from flock size, bird type, and season, plus feed cost per month and how long your feed supply will last.
Chicken Feed Amount Formula
F = N * R * M * S * (1 + W/100)
- F is the total feed your flock needs per day (grams)
- N is the number of birds
- R is the base intake per bird per day (grams), set by bird type
- M is the management factor (1.0 confined, 0.9 semi free range, 0.75 free range)
- S is the season factor (1.0 mild, 0.95 hot, 1.12 cold)
- W is extra feed added above modeled intake, not the fraction of purchased feed wasted
The calculator’s second mode answers how long your current feed supply will last:
D = A / F
- D is the number of days your feed will last
- A is the amount of feed on hand (same weight unit as F)
When you enter a feed price and your hens’ lay rate, the calculator also finds your feed cost per dozen eggs:
CPD = (r * 7 * p) / (E / 12)
- CPD is the feed cost per dozen eggs ($)
- r is the feed one hen uses per day, including waste (lb or kg)
- p is the feed price per lb or per kg
- E is the eggs one hen lays per week
In the daily feed mode, the calculator multiplies the base intake for your bird type by the management and season factors, adds your waste percentage, and reports per-bird and whole-flock amounts by day, week, and month, plus bags per month and monthly cost if you enter a bag size and price. In the supply mode, it divides feed on hand by the same allowance-inclusive daily feed mass to estimate days remaining. The date estimate uses the entered inventory date and whole elapsed days. Constant consumption is assumed.
Daily Feed Intake by Bird Type
The retained base rates below are source planning examples, not validated intake standards across each age range. Use measured consumption or supplier guidance for the actual birds. The custom rate option allows a measured grams-per-bird-per-day value; range and season factors are also scenarios rather than guaranteed reductions.
| Bird type | Per bird per day | Per bird per month |
|---|---|---|
| Chick (0 to 8 weeks) | 1 oz (30 g) | 2 lb (0.9 kg) |
| Bantam | 1.8 oz (50 g) | 3.3 lb (1.5 kg) |
| Pullet / grower (8 to 20 weeks) | 3.2 oz (90 g) | 6 lb (2.7 kg) |
| Laying hen (standard) | 4.1 oz (115 g) | 7.6 lb (3.5 kg) |
| Dual-purpose breed | 4.9 oz (140 g) | 9.3 lb (4.2 kg) |
| Broiler / meat bird | 6 oz (170 g) | 11.2 lb (5.1 kg) |
Feed Cost per Dozen Eggs by Lay Rate
The table below is a separate arithmetic example using 1.75 lb per hen per week, which differs from the calculator’s 115 g/day source scenario. Actual intake and laying rate vary. The parenthetical lay-rate descriptions are illustrative rather than predictions for an age group.
| Eggs per hen per week | Feed per dozen eggs | Cost per dozen at $0.40/lb | Cost per dozen at $0.60/lb |
|---|---|---|---|
| 3 (older hens) | 7.0 lb | $2.80 | $4.20 |
| 4 (average backyard) | 5.25 lb | $2.10 | $3.15 |
| 5 (good layer) | 4.2 lb | $1.68 | $2.52 |
| 6 (peak production) | 3.5 lb | $1.40 | $2.10 |
Chicken Feed Amount Example
Example 1: You keep 12 standard laying hens in a coop and run, in mild spring weather, with an average feeder (10% waste). Base intake is 115 g, and both the management and season factors are 1.0. Per hen, feed used is 115 * 1.0 * 1.0 * 1.10 = 126.5 g per day. The flock needs 12 * 126.5 = 1,518 g, or about 3.35 lb per day, which is roughly 100 lb per month, almost exactly two 50 lb bags.
Example 2: For 50 lb on hand and 8 hens, the retained pasture/winter scenario gives 115 × 0.75 × 1.12 = 96.6 g intake per hen per day. With the default 10% extra allowance, daily stock use is 8 × 96.6 × 1.10 = 850.08 g. Duration = (50 × 453.59237) / 850.08 = about 26.68 days. Actual forage and consumption must be checked; this is not a ration recommendation.
FAQ
How much feed does one chicken need per day? The default layer scenario is 115 g/day before adjustments. Intake depends on bird size, age, diet and conditions. A cup is a volume and has no fixed feed mass; weigh the feed or use an appropriate supplier measurement. A single chick or broiler rate cannot predict consumption throughout growth.
Why do free-range chickens need less purchased feed? Forage intake and nutritional value vary. The calculator’s 0.90 and 0.75 multipliers retain source scenarios; they do not establish that pasture replaces 10% or 25% of a balanced ration. Follow complete-feed supplier guidance and measured consumption rather than restricting feed from these factors.
Should I feed more in winter? Intake may change in cold weather, but a fixed temperature threshold and percentage do not apply to all flocks. The winter multiplier of 1.12 is an illustrative source assumption. Keep the diet nutritionally complete and follow guidance for the specific birds and housing.
