Cattle weight calculator: weigh a cow with a measuring tape
Most farms have no weighbridge, but nearly everyone has a measuring tape. This cattle weight calculator estimates the live weight of a cow, bull, buffalo, sheep, goat or pig from two measurements — heart girth round the chest and body length from shoulder to pin bone — in centimetres or inches, and gives the answer in kg and lb.
The main answer uses Schaeffer’s formula, the one printed on many weigh-tape guides and taught by extension services. For cattle the calculator also shows two heart-girth regressions from a published study of zebu crossbred cattle, so you can see how much the methods agree, and you can add an equation from a study of your own breed.
How to use the cattle weight calculator
- Choose the animal and whether your tape reads in centimetres or inches.
- Stand the animal squarely on level ground with its head up. Measure the heart girth just behind the front legs and shoulder blades, keeping the tape snug.
- Measure the body length in a straight line from the point of the shoulder to the pin bone. For pigs, measure from between the ears to the base of the tail.
- Read the estimated weight in kg and lb and compare the methods in the table.
- Copy the result, or carry the weight into the cattle feed calculator for a ration.
Cattle Weight Calculator features
Schaeffer’s formula
Girth² × length ÷ 300 (inches → lb) for cattle, buffalo, sheep and goats; ÷ 400 for pigs, with the +7 lb correction for pigs under 150 lb.
cm or inches, kg or lb
Type in either unit; switching converts the numbers you entered.
Girth regressions for comparison
Heart-girth equations by age and sex for zebu crossbred cattle, flagged when outside the weights studied.
Your own equation
Enter the a, b and c of a local study for your breed.
Diagram
Shows exactly where to place the tape.
Cow weight formula in kg and lb
Weight (lb) = heart girth (in) × heart girth (in) × body length (in) ÷ 300. In metric units the same formula is weight (kg) = girth (cm)² × length (cm) ÷ 10,839.
Example: a cow with a 70-inch girth and 78-inch body length weighs about 70 × 70 × 78 ÷ 300 = 1,274 lb (578 kg). A cow measuring 170 cm round the chest and 150 cm long weighs about 170 × 170 × 150 ÷ 10,839 = 400 kg.
Buffalo, sheep and goats use the same divisor of 300; pigs use 400. For horses there is a separate horse weight calculator.
Heart-girth equations for zebu crossbred cattle
From Rashid and colleagues (2016, Asian Journal of Medical and Biological Research), who measured 210 Brahman × local zebu cattle aged 6–36 months and weighing 63–535 kg; heart girth alone explained about 93% of the variation in weight. They were derived for zebu-type crossbred cattle and may not suit other breeds. A regression with published coefficients for Indian breeds could not be confirmed, so use the custom equation row if you have one from your state veterinary university.
| Group | Weight (kg) from heart girth HG (cm) |
|---|---|
| All animals | 4.07 × HG − 356 |
| Up to 12 months | 2.71 × HG − 191 |
| 12–24 months | 4.05 × HG − 357 |
| Over 24 months | 4.87 × HG − 471 |
| Males | 4.17 × HG − 369 |
| Females | 3.88 × HG − 333 |
| With body length BL (cm) | 2.83 × HG + 1.80 × BL − 392 |
How to measure accurately
- Measure when the animal is standing square, before feeding and watering if you can — a full rumen adds weight.
- Take each measurement two or three times and use the average; one centimetre of girth changes the result by more than a kilogram.
- Part long hair or wool so the tape lies on the body.
- Use the same tape and the same person each time to track growth; the trend is more reliable than any single estimate.
Cattle Weight Calculator FAQ
How do I calculate a cow’s weight in kg?
Measure heart girth and body length in cm, then weight (kg) = girth × girth × length ÷ 10,839. A 170 cm girth and 150 cm length gives about 400 kg.
How accurate is a cattle weight tape?
Good enough for routine management, but not exact: breed, body condition, pregnancy and gut fill all change the result, and different formulas can disagree by 10% or more — compare the methods in the table. A weighbridge is best for exact doses or sale.
Does the formula work for buffalo?
Field workers use the same girth² × length ÷ 300 formula for buffalo; keep the tape snug over the dewlap and brisket, and treat the figure as an approximation.
Can I calculate weight from heart girth only?
Yes, with a regression such as 4.07 × girth − 356 for zebu crossbred cattle. These depend on breed and age, so the girth-plus-length formula is usually more dependable.
How do I estimate a goat’s or pig’s weight?
Choose Sheep / goat or Pig. Goats and sheep use girth² × length ÷ 300; pigs use ÷ 400, with 7 lb added for pigs under 150 lb.
Is this a substitute for a scale?
No. It is an estimate for routine management. Weigh animals before medicine doses that depend on weight, or ask your veterinarian.