Calculator
Benadryl dosage calculator.
The standard 1 mg/lb diphenhydramine dose, with a tablet-count breakdown for the US OTC sizes (12.5 mg, 25 mg, 50 mg). Read the antihistamine-vs-anxiety distinction first — Benadryl is not an anxiety drug.
Read first
Benadryl is an antihistamine, not an anxiety medication.
Diphenhydramine (Benadryl) treats allergies, mild allergic reactions, and motion sickness. The drowsiness some dogs get is a side effect, not a reliable anxiety treatment — and many dogs experience paradoxical excitementinstead of calm. If your dog has anxiety, the right tools are L-theanine, alpha-casozepine, melatonin, or prescription anxiolytics like trazodone, gabapentin, or Sileo — not Benadryl.
This calculator helps you reach the standard 1 mg per poundantihistamine dose — useful for known allergic reactions on your vet’s advice. Always confirm with a vet before dosing, especially for dogs on other medications or with heart, liver, or eye conditions.
Your dog’s weight
Enter weight to calculate dose
Calculator covers dogs from 1 lb to 250 lb.