Swine Growth Rate Calculator
Average daily gain (ADG) is the primary metric for evaluating growth performance in pigs and is calculated simply as total weight gained divided by the number of days on feed. Monitoring ADG allows producers to track whether nutrition, health, and management practices are meeting expected growth targets. This calculator computes ADG from start and end weights and days on feed, and also estimates the number of days required to reach a target market weight from the current weight at the recorded ADG. Typical market hogs achieve ADG values of 0.8 to 1.0 kg per day under good commercial conditions.
Swine growth rate formula
ADG (kg/day) = (End weight - Start weight) / Days on feed
Days to market = (Market target weight - Current weight) / ADG
ADG is calculated over a defined growth period. To estimate days remaining to reach market weight, the current end weight and the calculated ADG are used. This projection assumes ADG remains constant, which is reasonable over short intervals but will vary with feed phase changes and age-related growth deceleration.
Interpreting swine growth performance
- Nursery pigs (7-25 kg): target ADG of 0.4-0.6 kg/day depending on age and diet phase.
- Grow-finish pigs (25-115 kg): target ADG of 0.75-1.0 kg/day under commercial conditions.
- A drop in ADG often signals a health challenge, nutritional problem, or environmental stressor before other signs appear.
- Compare ADG against genetic potential benchmarks provided by the genetic supplier for your herd.
- Weigh pigs on a calibrated scale; visual estimates introduce significant error in ADG calculations.
Swine growth rate calculator: frequently asked questions
What is average daily gain (ADG) in swine?
Average daily gain is the average amount of body weight a pig gains per day over a defined period. It is calculated as total weight gained divided by number of days. ADG is one of the most important growth performance metrics in commercial swine production.
What is a typical ADG for market hogs?
Modern commercial market hogs typically achieve ADG values of 0.8 to 1.0 kg per day (1.75 to 2.2 lb/day) from weaning to market weight. Superior genetics and optimized nutrition can push ADG above 1.0 kg/day. Actual ADG varies with genetics, nutrition, health status, and environment.
How is days to market calculated?
Days to market from current weight = (Market target weight - Current weight) / ADG. For example, a pig currently at 60 kg targeting 115 kg market weight with an ADG of 0.9 kg/day needs (115 - 60) / 0.9 = 61 days to reach market weight.
How does ADG relate to feed conversion?
ADG and feed conversion ratio (FCR) are related: FCR = daily feed intake / ADG. A pig eating 2.5 kg/day with an ADG of 0.9 kg/day has an FCR of 2.5 / 0.9 = 2.78. Higher ADG with the same feed intake means better FCR. Both metrics are used to evaluate production efficiency.
What factors most affect pig ADG?
Key factors: genetics (modern terminal sire breeds have high growth potential), dietary energy and protein levels matched to the pig's stage of growth, health status (respiratory and enteric disease reduce ADG significantly), temperature (cold increases energy for maintenance; heat causes reduced feed intake), and feeder space allowance.
Official sources
- National Research Council. Nutrient Requirements of Swine. National Academies Press: nap.edu.
- USDA Agricultural Research Service: ARS Homepage.
Reviewed by the CalculatorHub team, edited by James Graham, 15 June 2026. See our methodology.