How the dog chocolate toxicity calculator works
Chocolate contains theobromine and caffeine, which dogs process very slowly. The danger depends on how much theobromine your dog ate per kilogram of body weight, and darker chocolate contains far more.
Dose (mg/kg) = Theobromine ÷ Dog's weight in kg
The calculator uses approximate theobromine levels from the Merck Veterinary Manual: white chocolate about 0.25 mg/oz, milk about 58, semisweet and dark about 150, unsweetened baking chocolate about 390 and dry cocoa powder up to about 737. Merck reports mild signs at around 20 mg/kg, heart effects at 40 to 50 mg/kg and seizures at 60 mg/kg and above. Individual dogs can react at lower doses, and the cocoa content of dark chocolate varies a lot.
Worked example
A 20 lb (9.1 kg) dog eats 2 oz of milk chocolate: about 116 mg of theobromine, or 12.8 mg/kg, a low risk of more than mild stomach upset. If the same dog ate 2 oz of dark chocolate (300 mg), the dose would be 33 mg/kg, a moderate risk that needs a vet's advice right away.
Frequently asked questions
How much chocolate is toxic to a dog?
Mild signs can start at about 20 mg/kg of theobromine. That is roughly 1 oz of milk chocolate per 6 lb of dog, or 1 oz of dark chocolate per 16 lb.
What are the signs of chocolate poisoning?
Vomiting, diarrhea, thirst, panting, restlessness, a racing heart, tremors and, at high doses, seizures.
Is white chocolate safe for dogs?
It has almost no theobromine, but the fat and sugar can still cause stomach upset or pancreatitis.
Who do I call?
Your vet or an emergency clinic. The ASPCA Animal Poison Control Center is at (888) 426-4435 and Pet Poison Helpline at (855) 764-7661; both may charge a consultation fee.
Updated October 2026. Results are estimates for education, not financial or medical advice. All math runs in your browser; nothing you type is sent anywhere.