Weight tracking
Cattle weight tracking from a tape measure or a typed-in weight
Dairy Vitals estimates a cow's weight from two tape measurements, the heart girth and the body length, using the formula heart girth squared times body length divided by 10,840 (centimetres in, kilograms out). Use the free calculator with no account, or save each estimate with the animal. If you already know an animal's weight, you can also type it in with a date. Either way you follow her weight over time. A tape estimate is not a scale reading, and an entered weight is the figure you typed: Dairy Vitals does not check it against a scale.
Free for up to 30 animals. No credit card required.
Two tape readings, in centimetres or inches.
Heart girth
180 cm
Body length
150 cm
180 × 180 × 150 ÷ 10,840 = 448 kg (988 lb)
Estimated weight over time
How weight tracking works
Step 1: Measure the animal.
Put a soft tape around the chest just behind the front legs for the heart girth, and measure the body length in a straight line from the point of the shoulder to the point of the buttock. Centimetres or inches both work.
Step 2: Get the estimate.
Type the two numbers into the calculator and it shows the weight in kilograms and pounds, rounded to a whole number.
Step 3: Save it with the animal.
When you are signed in, choose the animal, the date and an optional note, and save the measurement. Only the two tape readings are entered; the weight is always calculated.
Step 4: Or enter a weight.
If you already know it, open the Enter a weight tab, choose the animal, the date and the weight in kilograms. It is saved exactly as you typed it, with no tape readings.
Step 5: Watch the history.
Each animal gets a weight history with a chart and the change since the previous weight, and it says whether each weight was estimated or entered.
Step 6: Compare over time.
Pick a date range to see each animal's first and latest weight, the change and the average kilograms per day, or download the comparison as a CSV file.
What you can do
A free calculator
The calculator on the website needs no account and saves nothing. Enter the heart girth and body length in centimetres or inches and get kilograms and pounds.
A check on your measurements
A reading that is zero, not a number or implausibly large is refused with a message. One that is outside the usual range for cattle still gives an estimate, with a note to double-check the measurement and the unit.
Saved weights for each animal
Save the two tape readings, the date and an optional note with an animal, from the Weight tab or from the animal's own page.
Enter a weight directly
If you already know an animal's weight, type it in kilograms with the date and an optional note, with no tape readings. It is saved as you typed it, and the history marks it as entered rather than estimated.
Weight history and chart
See every saved weight for an animal, a chart of her weight over time with a different marker for entered weights, and the change since the last weight.
A comparison report
Choose a date range and see, for each animal, the first and latest weight, the change, the number of days and the average kilograms per day. A row that compares an estimate with an entered weight says so. Download it as a CSV file.
Team-friendly editing
Owners and managers can edit or delete any saved weight; workers can change the ones they saved themselves.
On every plan
The calculator, saved and entered weights and the comparison report are included on every plan, and saved weights do not count towards your animal limit.
Worth knowing. A tape result is an estimate from a standard formula. Real weight varies with breed, age, body condition and how carefully you measure, and there is no breed or age correction. A weight you type in is saved exactly as typed and is not checked. Do not use an estimate to work out medicine doses: use a scale or ask a vet.
Who it is for
Weight tracking is for farms without a scale, or without one that is easy to use, that still want a rough idea of how heifers, calves and cows are growing or holding condition, and for farms that already know some weights and want to keep them next to the estimates. It suits smallholders and larger herds alike, and anyone can try the calculator for free before creating an account.
Also in Dairy Vitals
- Fertility trackingHeats, inseminations, pregnancy outcomes and treatments for each animal, with the status and the next dates worked out for you.Learn more →
- Milk productionRecord the litres from every milking per animal, or as the farm's total, then see the farm's totals, a chart of the last month and what is still to log.Learn more →
- Feed and expense trackingRecord the feeds you use, per bag or per kg, the farm's expenses such as salaries and bills, and what a treatment or an insemination cost, then see a monthly summary of what you recorded. On every plan, including Free.Learn more →
- Deworming scheduleWrite your farm's own deworming schedule once, see when each animal is due and record doses for one animal or the whole herd. On the Starter and Growth plans.Learn more →
Frequently asked questions
How does Dairy Vitals estimate a cow's weight?
It multiplies the heart girth by itself, multiplies that by the body length, and divides by 10,840, with both measurements in centimetres. The answer is in kilograms and is also shown in pounds, rounded to a whole number. For example, a heart girth of 180 cm and a body length of 150 cm give about 448 kg.
How do I measure the heart girth and body length?
For the heart girth, pass a soft tape around the chest just behind the front legs and over the withers. For the body length, measure in a straight line from the point of the shoulder to the point of the buttock (the pin bone). Keep the animal standing square and measure both in the same unit.
How accurate is the estimate?
It is an estimate, not a scale reading. Real weight varies with breed, age, body condition and how carefully you measure, and the formula has no breed or age correction. It is most useful for following whether an animal is growing or holding condition from one measurement to the next.
Can I use the estimate to work out medicine doses?
No. The estimate is a guide only. For anything where the exact weight matters, such as medicine doses, use a scale or ask your vet.
Do I need an account to use the calculator?
No. The calculator on the website is free for everyone, needs no account and saves nothing: what you type stays in your browser. To save weights with an animal and compare them over time you need a free account and a farm.
Can I save weights and see how an animal's weight changes?
Yes. You can save a tape estimate with an animal, or type in a weight you already know, each with a date and a note. The animal's page then shows every saved weight, a chart and the change since the previous one, and says which weights were estimated and which were entered. The comparison report shows each animal's first and latest weight over a date range and can be downloaded as a CSV file.
Can I enter a weight myself instead of measuring with a tape?
Yes. Open the Enter a weight tab (or Add a weight on the animal's page), choose the animal, the date and type the weight in kilograms. It is saved exactly as you typed it, and Dairy Vitals does not check it against a scale. If a comparison covers an estimate and an entered weight, it says so, because an estimate can be off by several percent.
Is weight tracking free?
Yes. The calculator, saved and entered weights and the comparison report are included on every plan, including the Free plan for up to 30 animals, and saved weights do not count towards the animal limit.
More about the plans on the pricing page, or ask us a question.
Try weight tracking on your own herd
Create a free account, add your first animals and start recording today. No credit card needed.