Livestock Daily Gain Calculator
Two weighs and days to ADG, gain, and projection.
What it does
Average daily gain turns two scale readings into management. A steer adding 1.5 pounds a day is on track; one adding 0.8 on full feed is waving a flag. The arithmetic is simple division with real money behind it.
The tool above subtracts start from end weight, divides by days, and projects 30 days ahead at the same pace. Imperial mode works in pounds; metric mode works in kilograms. Both print ADG, total gain, and projection.
Extension beef, sheep, and swine guides report performance in ADG because rations, health, and genetics all land in one number. University trials compare pens this way, and cost of gain follows directly: feed cost per day divided by ADG.
Weigh right and the number tells truth. Same scale, same hour, empty gut, long intervals. Then read the band for the species: backgrounding cattle near 1.5 to 2.5, hogs near 1.6 to 2.0, lambs near 0.4 to 0.8 pounds a day.
How to use
- Pick imperial (lb) or metric (kg).
- Enter start and end weights from similar conditions.
- Enter whole days between weighs.
- Read ADG, total gain, and the 30-day projection.
- Compare ADG with the species band.
- Recheck monthly and fix limiters early.
Formula
- start
- Starting weight in lb (kg metric).
- end
- Ending weight in the same units.
- days
- Whole days between weighs.
Weights must share units (lb with lb, kg with kg) and come from comparable conditions. Projection holds ADG flat for 30 days; growth curves bend near finish, so treat it as a bearing, not a promise.
Worked example
Example: 150 lb in 100 days
Backgrounding steer, 500 to 650 lb over 100 days.
- Steer weighs 500 lb, then 650 lb after 100 days.
- Gain: 650 - 500 = 150 lb.
- ADG: 150 / 100 = 1.5 lb/day.
- Projection: 650 + 1.5 x 30 = 695 lb.
- Compare 1.5 against the species band in the table.
Reference table
| Stock | Typical ADG | Note |
|---|---|---|
| Backgrounding cattle | 1.5 to 2.5 lb/day | Growing, not finishing |
| Feedlot cattle | 2.5 to 4.0 lb/day | High energy rations |
| Hogs, grow-finish | 1.6 to 2.0 lb/day | Modern genetics |
| Lambs | 0.4 to 0.8 lb/day | Forage plus grain |
| Goats | 0.2 to 0.5 lb/day | Browse based |
Limits
- Needs honest weights; gut fill swings readings.
- Projection assumes flat growth; finish curves bend.
- Bands are typical ranges, not guarantees.
- Health and ration diagnosis needs a vet or agent.
Common mistakes
- Weighing full versus empty gut.
- Judging on two-week windows.
- Comparing across species bands.
- Ignoring parasites behind poor gain.
- Projecting straight to finish weight.
Try it yourself
Quick checks. Answers sit tucked under each question.
ADG for 400 to 520 lb in 80 days?
Gain is 120 lb. ADG is 120 / 80 = 1.5 lb/day. Projection is 520 + 45 = 565 lb.
ADG for 180 to 240 kg in 90 days?
Gain is 60 kg. ADG is 60 / 90 = 0.67 kg/day. Projection is 240 + 20 = 260 kg.
Questions
What is ADG?
Average daily gain: weight gained divided by days on feed. It distills growth, ration, and health into one comparable number that extension reports use everywhere.
How do I weigh accurately?
Same scale, same time of day, same gut fill (weigh before feeding and watering). Monthly weighs catch trends; daily weighs catch noise.
Why do short weighs mislead?
Short windows magnify error: a 2-lb scale swing over 14 days moves ADG by 0.14. Weigh over 60-plus days for decisions and use short checks only for alarms.
What moves ADG most?
Energy first, then protein, minerals, water, and health. Sick, parasitized, or heat-stressed stock gain poorly on full feed. Fix the limiter before adding grain.
What decisions use ADG?
Finish or ship dates, ration cost per pound of gain, and group comparisons. A pen gaining 1.5 against a 2.0 target is losing money daily.
Does this work for poultry or lambs?
Yes, with species bands: chicks gain ounces while steers gain pounds. The math is identical; only the expected band changes, so read the table row for your stock.