Pet Medication Dosage Calculator for Dogs and Cats
Look up weight-based dose ranges for common pet medications — with tablet & liquid conversions, safety warnings, and clear guidance on when to call your vet.
Dose ranges on this page are published veterinary references for education only. Your veterinarian's prescribed dose always wins. When in doubt, call your vet first.
Quick dose calculator
Browse by medication
Diphenhydramine (Benadryl)
Diphenhydramine — sold over the counter as Benadryl — is an antihistamine veterinarians commonly use in dogs for mild allergic rea…
Gabapentin (Neurontin)
Gabapentin is a prescription drug veterinarians use in dogs for chronic pain (including arthritis and nerve pain), seizures, and s…
Famotidine (Pepcid)
Famotidine — sold as Pepcid — is an H2 blocker that reduces stomach acid. Veterinarians use it in dogs for acid reflux, gastritis,…
Omeprazole (Prilosec)
Omeprazole (Prilosec) is a proton pump inhibitor (PPI) — a stronger and longer-lasting acid suppressant than famotidine. Veterinar…
Hydroxyzine (Atarax)
Hydroxyzine (Atarax, Vistaril) is an antihistamine veterinarians prescribe for dogs with itchy skin conditions such as atopic derm…
How to use this site
- Pick your pet's species and medication above, or open a full guide below.
- Enter weight in pounds or kilograms to get the published dose range.
- Convert to tablets or liquid — the calculator does the math for common sizes.
- Read the safety section on the drug's page, then confirm with your veterinarian before giving anything.
Why dose ranges, not exact doses?
Veterinary dosing is a range because the right dose depends on your pet's condition, age, weight, and other medications. We show the conservative end of published veterinary references and always point you to your vet for the final call. Numbers here are educational — never a prescription.
Frequently asked questions
Is this site a substitute for my veterinarian?
No. Every page states it clearly: this is educational information, not veterinary advice. Always consult your veterinarian before giving any medication to your pet.
Where do the dose numbers come from?
Published veterinary references — VCA Hospitals, PetMD, GoodRx Pet Health, the Merck Veterinary Manual, Plumb's, BSAVA client leaflets, and AAHA guidelines. Each drug page lists its sources, and we use the conservative end when sources differ.
Is the calculator really free?
Yes — every dose calculator on this site is free with no account needed. Pro ($9/month or $49 one-time) adds multi-pet medication plans and local dose reminders.
Can I use human medications for my pet?
Some human medications are used in veterinary medicine, but many combination products contain ingredients that are toxic to pets (pseudoephedrine, acetaminophen, xylitol). Each drug page lists exactly which products to avoid — and your vet should confirm before you give anything.
Dose ranges on this page are published veterinary references for education only. Your veterinarian's prescribed dose always wins. When in doubt, call your vet first.