Learning to track pig weight accurately is one of the highest-value habits on any pig farm — yet most small-scale farmers skip it entirely because they assume they need expensive equipment.
You don’t.
Why you must track pig weight
When you track pig weight consistently, you catch problems before they become expensive. A pig losing ground on weight gain is showing you a warning sign — poor feed quality, illness, pen stress — before any visible symptoms appear.
Most farmers only notice something is wrong when it’s already cost them money. Weekly weight tracking puts you ahead of it every time.
Method 1: The tape measure formula
This is the most accurate way to track pig weight without a scale. All you need is a flexible tailor’s measuring tape.
Measure two things: the heart girth (circumference around the chest just behind the front legs) and the body length (from base of ears to base of tail along the spine).
Then apply this formula: Weight (kg) = (Heart Girth cm × Heart Girth cm × Body Length cm) ÷ 14,400
Example: Heart girth 90cm, body length 100cm = 90 × 90 × 100 ÷ 14,400 = 56.25 kg. Accurate within 5–10% for most breeds — close enough for practical farm decisions.
Method 2: Body condition scoring
When you can’t measure, use visual scoring on a 1–5 scale. Score 1 = severely underweight, spine clearly visible. Score 2 = thin, ribs easily felt. Score 3 = ideal, ribs felt with firm pressure only. Score 4 = overweight, ribs very hard to feel. Score 5 = obese, ribs cannot be felt at all.
Market pigs should stay at 3. Breeding sows can reach 3.5 approaching farrowing.
How often to track pig weight
Grow-out pigs: once per week minimum. Breeding stock: once per month. The key is consistency — same method, same time of day, same conditions every time. Inconsistent method creates more error than the pig itself.
Always record what you measure
A weight you don’t record is worthless. You need the trend — one week’s number means nothing without last week’s to compare it to. Use a notebook, a spreadsheet, or an app like PigPal which stores per-pig weight history and shows the growth curve automatically.
Warning signs to watch for
A healthy grower should gain 0.5–0.8 kg per day under good conditions. Two consecutive weeks of no gain means investigate immediately — check feed quality, pen conditions, and health. Any sudden weight loss means call your vet that day.
The bottom line
You don’t need expensive equipment to track pig weight and make better decisions. A tape measure, a consistent method, and a place to record the numbers is all it takes. Start with five pigs this week. Measure them. Write it down. Do the same next week. You’ll be surprised how much clarity it gives you.
Weighing your pigs regularly is one of the most important things you can do as a pig farmer — but most small-scale farmers skip it because they don’t have a livestock scale.
The good news: you don’t need one.
Why tracking weight matters
Weight gain tells you everything. A pig that’s eating well and staying healthy will gain weight consistently. A pig that’s losing ground — or not gaining at all — is giving you a warning sign before any visible symptoms appear.
Most farmers only notice a problem when it’s already expensive. Tracking weight puts you ahead of it.
Method 1: The tape measure formula
This is the most accurate low-cost method. You need a tailor’s measuring tape — the flexible kind used for sewing.
Measure two things: Heart girth — wrap the tape around the pig just behind its front legs. Body length — measure from the base of the ears to the base of the tail along the spine.
Formula: Weight (kg) = (Heart Girth cm × Heart Girth cm × Body Length cm) ÷ 14,400
Example: A pig with heart girth 90cm and body length 100cm = 90 × 90 × 100 ÷ 14,400 = 56.25 kg. Accurate to within 5–10% for most breeds.
Method 2: Body condition scoring
Score your pigs 1–5 based on how they look and feel. 1 = severely underweight, spine visible. 2 = thin, ribs easily felt. 3 = ideal, ribs felt with firm pressure. 4 = overweight, ribs hard to feel. 5 = obese, ribs cannot be felt.
Most market pigs should sit at a 3. Breeding sows can go to 3.5 before farrowing.
How often should you weigh?
Grow-out pigs: once a week. Breeding stock: once a month. Same method, same time of day, every time.
Record it every time
A measurement you don’t record is a measurement wasted. Use a notebook, spreadsheet, or an app like PigPal that stores weight history per pig and shows the trend automatically.
What to look for
A grower pig should gain 0.5–0.8 kg per day under good conditions. Two consecutive weeks of no gain — investigate immediately. Sudden weight loss — call your vet.
The bottom line
You don’t need expensive equipment to make data-driven decisions on your farm. A tape measure, a consistent method, and a place to record the numbers is all it takes. Start this week.