Pet Insulin Dose Calculator
Insulin dosing for a diabetic pet is highly individual and is set and adjusted only by a veterinarian based on blood glucose monitoring. This tool does the arithmetic on figures your vet gives you: total units equal body weight in kilograms times the starting dose rate in units per kilogram, and the syringe volume equals total units divided by the insulin concentration (40 for U-40, 100 for U-100). Use the matching syringe for the concentration. Enter weight, the vet-supplied dose rate, and the concentration. Never change a dose without veterinary direction: too much insulin can cause dangerous low blood sugar.
Insulin dose formula
Weight (kg) = pounds / 2.2046226
Total dose (units) = weight (kg) * dose rate (units/kg)
Syringe volume (mL) = total dose (units) / concentration (units/mL)
Read the dose in units on a syringe that matches the concentration (U-40 syringe for U-40 insulin, U-100 for U-100). The millilitre figure is a cross-check, not the primary measure.
Insulin safety context
- The dose rate, insulin type, and schedule are set only by a veterinarian.
- Always pair the correct syringe with the insulin concentration.
- Never change a dose without veterinary direction.
- Too much insulin can cause life-threatening hypoglycaemia.
- If your pet is not eating or you suspect a dosing error, call your vet first.
Pet insulin: frequently asked questions
How is an insulin dose worked out for a pet?
Total units equal body weight in kilograms times the starting dose rate in units per kilogram that your veterinarian provides. The syringe volume in millilitres equals the total units divided by the insulin concentration (units per millilitre), for example 40 for U-40 insulin or 100 for U-100. Every figure must come from your veterinarian and the product.
Why must the dose rate come from my veterinarian?
Insulin dosing is highly individual and is adjusted based on blood glucose monitoring over time. There is no safe generic dose. The starting dose rate, the insulin type, and the schedule are set and adjusted only by a veterinarian. This tool simply does the arithmetic on figures your vet gives you.
What is the difference between U-40 and U-100 insulin?
U-40 insulin contains 40 units per millilitre and U-100 contains 100 units per millilitre. You must use the matching syringe: a U-40 syringe with U-40 insulin, a U-100 syringe with U-100 insulin. Mismatching the syringe and the concentration causes serious dosing errors.
Can I change my pet's insulin dose myself?
No. Never adjust an insulin dose without veterinary direction. Too much insulin can cause life-threatening low blood sugar (hypoglycaemia). Dose changes are made by your veterinarian based on glucose curves and your pet's response.
What should I do if I am unsure about a dose?
Contact your veterinarian before giving insulin if anything is unclear, if your pet is not eating, or if you suspect a missed or double dose. When in doubt, it is safer to delay and call than to risk an overdose.
Official sources
- U.S. FDA Center for Veterinary Medicine: Animal drug safety and labelling.
- Merck Veterinary Manual: Diabetes mellitus in dogs and cats.
Reviewed by the CalculatorHub team, edited by James Graham, 17 June 2026. See our methodology.