Deworming Dose & mg/kg & Volume per Animal
Doses cattle
The anthelmintic dose is set by body weight at mg per kg, and the volume = total dose ÷ the product's concentration — dose to the heaviest, never underdose to avoid breeding resistance.
Calculate the deworming dose
Next: draw 12 mL per head and carry roughly 120 mL for the 10 animals; dose to the heaviest in the group and never underdose — sub-lethal doses breed resistant worms.
Weigh, don't guess. Rotate active classes, observe meat/milk withdrawal periods, and follow the product label and your vet's advice.
Deworming dose — key facts
- Total dose
- weight × dose rate (mg/kg)
- Volume
- total dose ÷ concentration
- Dose to
- the heaviest in the group
- Never
- underdose — breeds resistance
- Concentration
- mg per mL from the label
- Vary in size?
- split into weight groups
- Outputs
- dose, volume/animal, total
- Privacy
- Runs in your browser; nothing uploaded
Right dose, right volume, no underdosing
Deworming goes wrong in two quiet ways: a guessed weight and an underdose. Anthelmintics work at a set amount of active ingredient per kilogram of body weight, so the dose must be calculated — total dose = weight × the mg/kg rate — and then converted to a measurable volume by dividing by the product's concentration. Dose to the heaviest animal in the group and never underdose, because the worms that survive a weak dose are exactly the ones that breed resistance.
This tool gives the total dose, the volume per animal, the total volume and the animal count from your inputs, so you draw up the right amount with confidence. Use it alongside an accurate body weight and your product label. Pair it with the Water Medication, Animal Weight Estimator and Livestock Water Requirement tools for a complete herd-health plan.
Dose by weight
Total mg from body weight and mg/kg rate.
Get the volume
Convert mg to mL via concentration.
Beat resistance
Dose to the heaviest; never underdose.
Draw the total
Volume per animal scaled to the group.
Frequently Asked Questions
What does this calculator do?+
It works out how much dewormer (anthelmintic) each animal needs. From the body weight and the dose rate in mg per kg it gives the total dose in mg, then divides by the product's concentration to give the volume per animal, and multiplies by the number of animals for the total volume to draw up.
How is the dose worked out?+
Anthelmintic dose is set by body weight: total dose (mg) = body weight (kg) × dose rate (mg/kg). The volume to give = total dose ÷ the product's concentration (mg per mL). So a heavier animal needs more product, and a more concentrated product needs less volume for the same dose.
Why dose by body weight?+
Dewormers work at a target amount of active ingredient per kilogram of the animal. Too little and the worms survive; too much wastes product and risks toxicity. Dosing by weight delivers the right amount of drug for each animal's size, which is why an accurate weight — not a guess — matters.
Why dose to the heaviest in a group?+
When you treat a group at one dose, set it to the heaviest animal so none are underdosed. Underdosing leaves some worms exposed to a sub-lethal amount of drug, and the survivors that tolerate it pass on resistance. Dosing to the top weight in the group is a standard safeguard against that.
What is anthelmintic resistance?+
Resistance is when worm populations evolve to survive a dewormer that used to kill them, so the product stops working. Underdosing and over-frequent treatment are major drivers. Calculating the correct dose, dosing to the heaviest, and not deworming more often than needed all help slow resistance and keep your dewormers effective.
What is product concentration?+
Concentration is how much active ingredient the product contains per unit volume — for example mg per mL for a drench or injectable. The calculator divides the total mg dose by this concentration to convert it into the millilitres you actually measure and give. Always read it from your product's label.
Should I split the group by weight?+
If animals vary a lot in size, weigh and split them into weight groups and dose each group to its own heaviest member, rather than dosing the whole mob to the single biggest animal. That treats lighter animals accurately without wasting product, while still avoiding underdosing within each group.
How do I estimate body weight without scales?+
Use a weigh band or the heart-girth method, or the Animal Weight Estimator, which estimates weight from girth and length. An accurate weight is essential for an accurate dose — if anything, err toward the heavier side within the group so you don't underdose.
Are the figures precise?+
The arithmetic is exact for the weight, dose rate and concentration you enter. The clinical correctness depends on using the right dose rate for the product and parasite, an accurate body weight, correct administration and withdrawal periods. Always follow the product label and a vet's advice for treatment decisions.