Flea/Tick/Heartworm Dose Calculator
Identify the correct weight band product size and annual treatment cost.
About Flea/Tick/Heartworm Dose Calculator
Parasite treatments are supplied in weight bands, so the correct product is determined by which band the animal falls into rather than by calculation. Animals near a band boundary should be weighed rather than estimated. Splitting a large-dog dose between small animals is dangerous because the concentration is not uniform and some active ingredients are toxic to cats.
Formula
Flea/Tick/Heartworm Dose
Doses = weeks in the period ÷ treatment interval, rounded up
- weight band
- Products are supplied in fixed bands rather than by exact weight
- interval
- Monthly for most spot-on products, longer for some oral treatments
Worked example
With the default values below, Flea/Tick/Heartworm Dose Calculator returns Product Weight Band of Large, 10 to 25 kg. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Body weightminimum 0.1 kg
- 20 kg
- Treatment intervalminimum 1 weeks
- 4 weeks
- Cost per doseminimum 0
- 12.5
- Months of coverage neededaccepts 1–12
- 12
Results
- Product Weight Band
- Large, 10 to 25 kg
- Doses Required
- 14
- Total Cost for the Period
- $175.00
- Annualised Cost
- $175.00
- Interval Between Doses
- 4 weeks
Step by step
- 1Values used
- 2Flea/Tick/Heartworm Dose
- 3Product Weight Band= Large, 10 to 25 kg
- 4Doses Required= 14
- 5Total Cost for the Period= 175.00
- 6Annualised Cost= 175.00
- 7Interval Between Doses= 4 weeks
Assumptions and limits
- The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax or compounding frequency into account.
- Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
- Parasite treatments are veterinary medicines. Use only products licensed for the species and weight, never divide or combine doses, and never apply a dog product to a cat. Some permethrin-based dog treatments are fatal to cats. Consult your veterinarian for the appropriate product.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Parasite treatments are veterinary medicines. Use only products licensed for the species and weight, never divide or combine doses, and never apply a dog product to a cat. Some permethrin-based dog treatments are fatal to cats. Consult your veterinarian for the appropriate product.
Frequently Asked Questions
How is Flea/Tick/Heartworm Dose calculated?
Doses = weeks in the period ÷ treatment interval, rounded up Parasite treatments are supplied in weight bands, so the correct product is determined by which band the animal falls into rather than by calculation. Animals near a band boundary should be weighed rather than estimated.
Why does Flea/Tick/Heartworm Dose matter?
Splitting a large-dog dose between small animals is dangerous because the concentration is not uniform and some active ingredients are toxic to cats.
What values do I need to enter?
This calculator takes 4 inputs: Body weight, Treatment interval, Cost per dose, Months of coverage needed. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.